Cationic polymers and porous materials

ABSTRACT

According to one or more embodiments, cationic polymers may be produced which include one or more monomers containing cations. Such cationic polymers may be utilized as structure directing agents to for mesoporous zeolites. The mesoporous zeolites may include micropores as well as mesopores, and may have a surface area of greater than 350 m2/g and a pore volume of greater than 0.3 cm3/g. Also described are core/shell zeolites, where at least the shell portion includes a mesoporous zeolite material.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application is a continuation of and claims priority to U.S.Non-Provisional patent application Ser. No. 16/153,122, filed Oct. 5,2018, which is a continuation of and claims priority to U.S.Non-Provisional patent application Ser. No. 16/043,791, filed Jul. 24,2018, which is a continuation of and claims priority to U.S.Non-Provisional patent application Ser. No. 15/298,647, filed Oct. 20,2016, which claims priority to U.S. Provisional Patent Application Ser.No. 62/244,388, filed Oct. 21, 2015, the entire contents of all of whichare incorporated by reference herein.

TECHNICAL FIELD

The present disclosure generally relates to cationic polymers and porousmaterials, and more specifically to cationic polymers that may beutilized in the synthesis of porous materials.

BACKGROUND

Microporous structures, such as zeolites, may be utilized in manypetrochemical industrial applications. For example, such microstructuresmay be utilized as catalysts in a number of reactions.

BRIEF SUMMARY

In accordance with one embodiment of the present disclosure, a cationicpolymer may comprise the structure depicted in Chemical Structure #3 orChemical Structure #8 that is included subsequently in the presentdisclosure.

In accordance with another embodiment of the present disclosure, thecationic polymer depicted in Chemical Structure #3 may be formed by aprocess comprising the steps of forming a diallyl methyl ammoniumhydrochloride cation with a chloride anion from diallylamine,polymerizing the diallyl methyl ammonium hydrochloride to form apoly(diallyl methyl ammonium hydrochloride) (PDMAH), forming apoly(diallyl methyl amine) (PDMA) from the poly(diallyl methyl ammoniumhydrochloride) (PDMAH), forming an ammonium halide cation with a halideanion by reacting a trialkyl amine with a dihaloalkane; and forming thechemical composition depicted in Chemical Structure #3 by reacting thePDMA with the ammonium halide cation.

In accordance with yet another embodiment of the present disclosure, acatalyst may be formed by utilizing the cationic polymer depicted inChemical Structure #3 as a structure-directing agent.

In accordance with yet another embodiment of the present disclosure, amesoporous zeolite may comprise a microporous framework comprising aplurality of micropores having diameters of less than or equal to 2nanometers (nm), and a plurality of mesopores having diameters ofgreater than 2 nm and less than or equal to 50 nm. The mesoporouszeolite may comprise an aluminosilicate material, a titanosilicatematerial, or a pure silicate material, the mesoporous zeolite maycomprise a Brunauer-Emmett-Teller (BET) surface area of greater than 350square meters per gram (m²/g), and the mesoporous zeolite may comprise apore volume of greater than 0.3 cubic centimeters per gram (cm³/g).Throughout this disclosure, surface area refers to the BET surface areaof a zeolite structure.

In accordance with yet another embodiment of the present disclosure, amesoporous zeolite may be produced by a method comprising combining acationic polymer and one or more precursor materials to form anintermediate material comprising micropores, and calcining theintermediate structure form the mesoporous zeolite. The cationic polymermay act as a structure-directing agent for the formation of themicropores. The cationic polymer comprises monomers that comprise two ormore quaternary ammonium cations or quaternary phosphonium cationsconnected by a hydrocarbon chain.

In accordance with yet another embodiment of the present disclosure, aporous material may comprise a zeolite core portion comprising amicroporous structure comprising a plurality of micropores having adiameter of less than or equal to 2 nm, where the core portion comprisesan aluminosilicate material, a titanosilicate material, or a puresilicate material. The porous material may also comprise a mesoporouszeolite shell portion that comprises an aluminosilicate material, atitanosilicate material, or a pure silicate material and surrounds thecore portion. The shell portion may comprise a microporous frameworkcomprising a plurality of micropores having diameters of less than orequal to 2 nm, and a plurality of mesopores having diameters of greaterthan 2 nm and less than or equal to 50 nm.

In accordance with yet another embodiment of the present disclosure, acore/shell zeolite comprising a core portion and a shell portion may beproduced by a method comprising forming the shell portion intermediatematerial around the core seed material, the shell portion intermediatematerial comprising micropores, and calcining the core/shell porousmaterial to form a core/shell zeolite, where the shell portion comprisesa mesoporous zeolite. The cationic polymer acts as a structure-directingagent for the formation of the micropores of the shell portionintermediate. The cationic polymer comprises monomers that comprise twoor more quaternary ammonium cations or quaternary phosphonium cationsseparated by a hydrocarbon chain.

Additional features and advantages of the technology disclosed in thisdisclosure will be set forth in the detailed description which follows,and in part will be readily apparent to those skilled in the art fromthe description or recognized by practicing the technology as describedin this disclosure, including the detailed description which follows,the claims, as well as the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of specific embodiments of thepresent disclosure can be best understood when read in conjunction withthe following drawings, where like structure is indicated with likereference numerals and in which:

FIG. 1 depicts a reaction pathway to formpoly(N¹,N¹-diallyl-N¹-methyl-N⁶,N⁶,N⁶-tripropylhexane-1,6-diamoniumbromide) (PDAMAB-TMHAB), according to one or more embodiments describedin this disclosure;

FIG. 2 depicts a schematic drawing of an MFI framework typemicrostructure, according to one or more embodiments described in thisdisclosure;

FIG. 3 depicts a Proton Nuclear Magnetic Resonance (H-NMR) spectrum ofPDAMAB-TMHAB as synthesized in Example 1, according to one or moreembodiments described in this disclosure;

FIG. 4 depicts N₂ sorption isotherms for the zeolite of Example 3 and aconventional ZSM-5 zeolite (without mesopores), according to one or moreembodiments described in this disclosure;

FIG. 5 depicts an X-ray diffraction (XRD) pattern of the zeolite ofExample 3 as-synthesized and following calcination, according to one ormore embodiments described in this disclosure;

FIG. 6 depicts a distribution curve of mesopore size in the zeolite ofExample 3, according to one or more embodiments described in thisdisclosure;

FIG. 7 depicts a Transmission Electron Microscope (TEM) image of thezeolite of Example 3, according to one or more embodiments described inthis disclosure;

FIG. 8 depicts a High Resolution Transmission Electron Microscope(HRTEM) image of the zeolite of Example 3, according to one or moreembodiments described in this disclosure;

FIG. 9 depicts a Fast Fourier Transform (FFT) image of the selected areashown in FIG. 8, according to one or more embodiments described in thisdisclosure;

FIG. 10 depicts a dark field Scanning Transmission Electron Microscope(STEM) image of the zeolite of Example 3, according to one or moreembodiments described in this disclosure;

FIG. 11 depicts XRD patterns of the zeolites of Example 6 which wereprepared having varying Si/Al molar ratios, according to one or moreembodiments described in this disclosure;

FIG. 12 depicts an HRTEM image of the silicate material of Example 5,according to one or more embodiments described in this disclosure;

FIG. 13 depicts a TEM image of the titanosilicate material of Example 4,according to one or more embodiments described in this disclosure;

FIG. 14 depicts an XRD pattern of the titanosilicate material of Example4, according to one or more embodiments described in this disclosure;and

FIGS. 15A-15D depict TEM images of ZSM-5 core/ZSM-5 shell porousstructures where FIG. 15A depicts the core (that is, the seed)materials, FIG. 15B depicts a core shell structure with a shellthickness of about 40 nm, FIG. 15C depicts a core shell structure with ashell thickness of about 100 nm, and FIG. 15D depicts a core shellstructure with a shell thickness of about 150 nm, according to one ormore embodiments described in this disclosure;

FIGS. 16A and 16B depict TEM images of zeolite Y core/mesoporous ZSM-5shell porous structures where the image of FIG. 16A is of seed zeolite Yseed materials and the image is FIG. 16B is of the core/shell porousstructure, according to one or more embodiments described in thisdisclosure;

FIG. 17A depicts TEM images for synthesized mesoporous Beta zeolites,FIG. 17B depicts XRD patterns for synthesized mesoporous Beta zeolites,and FIG. 17C depicts N₂ adsorption isotherms for synthesized mesoporousBeta zeolites, according to one or more embodiments described in thisdisclosure;

FIGS. 18A and 18B depict TEM images of a Beta core/mesoporous Beta shellporous structure, according to one or more embodiments described in thisdisclosure;

FIG. 19A depicts TEM images for the zeolites of Example 6, FIG. 19Bdepicts electron diffraction (ED) patterns for the zeolites of Example6, FIG. 19C depicts a high resolution TEM image for the zeolites ofExample 6, and FIG. 19D depicts reconstructed electron tomographicvolume data for the zeolites of Example 6, according to one or moreembodiments described in this disclosure;

FIG. 20A depicts XRD data for the zeolites of Example 6, FIG. 20Bdepicts adsorption/desorption isotherm data for the zeolites of Example6, FIG. 20C depicts thermogravimetric analysis data for the zeolites ofExample 6, and FIG. 20D depicts NH₃-Temperature-Programmed Desorption(TPD) profiles for the zeolites of Example 6, according to one or moreembodiments described in this disclosure;

FIG. 21A shows the conversion percentage and selectivity of aromaticsfor various conventional and mesoporous zeolites utilized as catalystsfor a methanol to aromatics reaction, and FIG. 21B shows the conversionpercentage and yield of olefins for various conventional and mesoporouszeolites utilized as catalysts for a cracking reaction of canola oil,according to one or more embodiments described in this disclosure; and

FIG. 22 shows a high-angle annular dark field scanning transmissionelectron microscopy image of mesoporous ZSM-5 zeolite-supported Ptnanocrystals, according to one or more embodiments described in thisdisclosure;

FIG. 23 depicts 2,6-di-tertbutylpyridine (DTBP) base titration of acidsites on the three zeolite catalysts, according to one or moreembodiments described in this disclosure;

FIGS. 24A and 24B depict TEM images of conventional zeolites, accordingto one or more embodiments described in this disclosure;

FIG. 25A depicts a photograph of mesoporous ZSM-5 zeolite and nano ZSM-5conventional zeolite adsorption of PtCl₄ ²⁻ before centrifugation, andFIG. 25B depicts a photograph of mesoporous ZSM-5 zeolite and nano ZSM-5conventional zeolite adsorption of PtCl₄ ²⁻ following centrifugation,according to one or more embodiments described in this disclosure;

FIGS. 26A-26E depict images of a core/shell zeolite having a nano ZSM-5conventional zeolite core and a mesoporous ZSM-5 zeolite shell,according to one or more embodiments described in this disclosure;

FIGS. 27A-27D show images of Beta core/mesoporous Beta shell porousstructure, according to one or more embodiments described in thisdisclosure;

FIG. 28 shows N₂ adsorption isotherms for zeolites prepared with SDApolymers having different molecular weights, according to one or moreembodiments described in this disclosure;

FIG. 29 shows a TEM image of a mesoporous ZSM-5 zeolite particle and thecorresponding ED pattern, according to one or more embodiments describedin this disclosure;

FIGS. 30A-30D shows TEM images of protruding MFI (mordenite frameworkinverted) fibers taken at different incident angles, according to one ormore embodiments described in this disclosure;

FIG. 31 shows simplified schematic illustration of mesoporous ZSM-5zeolite with one or more staggered crystal structures, according to oneor more embodiments described in this disclosure;

FIGS. 32A-32D show SEM images, XRD data, and N₂ adsorption isotherms forcore/shell structures prepared from nano ZSM-5 conventional zeolite corematerials/seeds and mesoporous ZSM-5 zeolite shells having varying shellthickness, according to one or more embodiments described in thisdisclosure; and

FIGS. 33A and 33B depict TEM images of mesoporous ZSM-5 zeolites grownon bulk conventional zeolite Beta crystals, according to one or moreembodiments described in this disclosure.

Reference will now be made in greater detail to various embodiments,some embodiments of which are illustrated in the accompanying drawings.Whenever possible, the same reference numerals will be used throughoutthe drawings to refer to the same or similar parts.

DETAILED DESCRIPTION

This disclosure is directed to various embodiments of cationic polymersthat may be used as structure-directing agents (SDAs) for thefabrication of mesoporous zeolite materials. As used throughout thisdisclosure, “zeolites” refer to micropore-containing inorganic materialswith regular intra-crystalline cavities and channels of moleculardimension. The microporous structure of zeolites (for example, 0.3 nm to1 nm pore size) may render large surface areas and desirablesize-/shape-selectivity, which may be advantageous for catalysis. Themesoporous zeolites described may include aluminosilicates,titanosilicates, or pure silicates. In embodiments, the zeolitesdescribed may include micropores (present in the microstructure of azeolite), and additionally include mesopores. As used throughout thisdisclosure, micropores refer to pores in a structure that have adiameter of less than or equal to 2 nm and greater than or equal to 0.1nm, and mesopores refer to pores in a structure that have a diameter ofgreater than 2 nm and less than or equal to 50 nm. The cationic polymersmay function as dual-function templates for synthesizing the mesoporouszeolites, meaning that they act simultaneously as a template for thefabrication of the micropores and as a template for the fabrication ofthe mesopores. In embodiments, the mesoporous zeolites fabricated by theuse of the cationic polymers as SDAs may comprise microstructures (whichinclude micropores) characterized by an MFI (mordenite frameworkinverted) framework type or a BEA framework type. For example, themesoporous zeolites described may be characterized as ZSM-5 (that is,having an aluminosilicate MFI framework type), as TS-1 (that is, havinga titanosilicate MFI framework type), or as silicalite-I (that is,having a pure silicate MFI framework type). In other embodiments, themesoporous zeolites described may be characterized as Beta (that is,having an aluminosilicate BEA framework type).

The cationic polymers disclosed may comprise one or more monomers whicheach comprise multiple cationic functional groups, such as quaternaryammonium cations or quaternary phosphonium cations. The cationfunctional groups of the monomers may be connected by a hydrocarbonchain. Without being bound by theory, it is believed that the cationicfunctional groups may form or at least partially aid in forming themicrostructure of the mesoporous zeolite (for example, an MFI frameworktype or BEA framework type) and the hydrocarbon chains and otherhydrocarbon functional groups of the polymer may form or at leastpartially aid in forming the mesopores of the mesoporous zeolite.

The cationic polymers may comprise functional groups which are utilizedas SDAs for the fabrication of the zeolite microstructure. Suchfunctional groups, which are believed to form the zeolitemicrostructure, include quaternary ammonium cations and quaternaryphosphonium cations. Quaternary ammonium is generally depicted inChemical Structure #1 and quaternary phosphonium is generally depictedin Chemical Structure #2.

As used throughout this disclosure, the encircled plus symbols (“+”)show cationic positively charged centers. R groups (including R1, R2,R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, and R13) represent chemicalconstituents. One or more of the various R groups may be structurallyidentical or may be structurally different from one another.

In Chemical Structure #1 and Chemical Structure #2, R1, R2, R3, and R4may include hydrogen atoms or hydrocarbons, such as a hydrocarbon chain,optionally comprising one or more heteroatoms. As used throughout thisdisclosure, a “hydrocarbon” refers to a chemical or chemical moietycomprising hydrogen and carbon. For example, the hydrocarbon chain maybe branched or unbranched, and may comprise an alkane hydrocarbon chain,an alkene hydrocarbon chain, or an alkyne hydrocarbon chain, includingcyclic or aromatic moieties. In some embodiments, one or more of R1, R2,R3, or R4 may represent hydrogen atoms. As used throughout thisdisclosure, a heteroatom is a non-carbon and non-hydrogen atom. Inembodiments, quaternary ammonium and quaternary phosphonium may bepresent in a cyclic moiety, such as a five atom ring, a six atom ring,or a ring comprising a different number of atoms. For example, inChemical Structure #1 and Chemical Structure #2, the R1 and R2constituents may be part of the same cyclic moiety.

In one or more embodiments, the two cation moieties may form ionic bondswith anions. Various anionic chemical species are contemplated,including Cl⁻, Br⁻, F⁻, I⁻, OH⁻, ½SO₄ ²⁻, ⅓PO₄ ³⁻, ½S²⁻, AlO₂ ⁻. In someembodiments, an anion with a negative charge of more than 1-, such as2-, 3-, or 4-, may be utilized, and in those embodiments, a single anionmay pair with multiple cations of the cationic polymer. As usedthroughout this disclosure, a fraction listed before an anioniccomposition means that the anion is paired with more than one cation andmay, for example, be paired with the number of cations equal to itsnegative charge.

In one or more embodiments, two cations of a monomer may be separatedfrom one another by a hydrocarbon chain. The hydrocarbon chain may bebranched or unbranched, and may comprise an alkane hydrocarbon chain, analkene hydrocarbon chain, or an alkyne hydrocarbon chain, includingcyclic or aromatic moieties. In one embodiment, the length of thehydrocarbon chain (measured as the number of carbons in the chaindirectly connecting the two cations) may be from 1 to 10,000 carbonatoms, such 1 to 20 carbon atom alkane chains.

The cationic polymers described in this disclosure are generallynon-surfactants. A surfactant refers to a compound that lowers thesurface tension (or interfacial tension) between two liquids or betweena liquid and a solid, usually by the inclusion of a hydrophilic head anda hydrophobic tail. Non-surfactants do not contain such hydrophobic andhydrophilic regions, and do not form micelles in a mixture containing apolar material and non-polar material. Without being bound by theory, itis believed that the polymers described are non-surfactants because ofthe inclusion of two or more cation moieties which are joined by ahydrocarbon chain. Such an arrangement has polar charges on or near eachend of the monomer, and such an arrangement excludes the hydrophobicsegment from the polymer, and thus the surfactant behavior(self-assembly in solution). On the atomic scale, it is believed thatthe functional groups (for example, quaternary ammoniums) on the polymerdirect the formation of zeolite structure; on the mesoscale, the polymerfunctions simply as a “porogen” rather than an SDA in the conventionalsense. As opposed to the cases of surfactants, non-surfactant polymersdo not self-assemble to form an ordered mesostructure, which in turnfavors the crystallization of zeolites, producing a new class ofhierarchical zeolites that feature three-dimensionally (3-D) continuouszeolitic frameworks with highly interconnected intracrystallinemesopores. Such materials are advantageous over theirsurfactant-templated counterparts for applications where the structuralintegrity of zeolite is important while the ordering of mesopores isnot.

In one embodiment, the cationic polymer may comprise the generalizedstructure depicted in Chemical Structure #3:

Chemical Structure #3 depicts a single monomer of the cationic polymer,which is signified by the included bracket, where n is the total numberof repeating monomers in the polymer. In some embodiments, the cationicpolymer may be a copolymer comprising two or more monomer structures.The X⁻ and Y⁻ of Chemical Structure #3 represent anions. It should beunderstood that one or more monomers (such as that shown in ChemicalStructure #3) of the cationic polymers described in the presentapplication may be different from one another. For example, variousmonomer units may include different R groups. Referring to the ChemicalStructure #3, A may represent nitrogen or phosphorus and B may representnitrogen or phosphorus, R5 may be a branched or unbranched hydrocarbonchain having a carbon chain length of from 1 to 10,000 carbon atoms,such as a 2 to 20 carbon alkane, X⁻ may be an anion and Y⁻ may be ananion, and R6, R7, R8, R9, R10, R11, R12, and R13 may be hydrogen atomsor hydrocarbons optionally comprising one or more heteroatoms.

Referring to Chemical Structure #3, in one or more embodiments, A mayrepresent nitrogen or phosphorus and B may represent nitrogen orphosphorus. In one embodiment, A and B may be nitrogen, and in anotherembodiment, A and B may be phosphorus. For example, A of ChemicalStructure #3 may comprise a quaternary ammonium cation or a quaternaryphosphonium cation. As shown in Chemical Structure #3, A may be aportion of a ring structure, such as a five sided ring. In one or moreembodiments, X⁻ and Y⁻ are anions. For example, X⁻ may be chosen fromCl⁻, Br⁻, F⁻, I⁻, OH⁻, ½SO₄ ²⁻, ⅓PO₄ ³⁻, ½S²⁻, AlO₂ ⁻, and Y⁻ may bechosen from Cl⁻, Br⁻, F⁻, I⁻, OH⁻, ½SO₄ ²⁻, ⅓PO₄ ³⁻, ½S²⁻, AlO₂ ⁻. Inembodiments, an anion with a negative charge of more than 1-, such as2-, 3-, or 4-, may be present, and in those embodiments, a single anionmay pair with multiple cations of the cationic polymer.

Still referring to Chemical Structure #3, R5 represents a branched orunbranched hydrocarbon chain. The hydrocarbon chain may be branched orunbranched, and may comprise an alkane hydrocarbon chain, an alkenehydrocarbon chain, or an alkyne hydrocarbon chain. The length of thehydrocarbon chain (measured as the number of carbons in the chaindirectly connecting A to B) may be from 1 to 10,000 carbon atoms (suchas from 1 to 1,000 carbon atoms, from 1 to 500 carbon atoms, from 1 to250 carbon atoms, from 1 to 100 carbon atoms, from 1 to 50 carbon atoms,from 1 to 25 carbon atoms, from 1 to 20 carbon atoms, from 1 to 15carbon atoms, from 1 to 10 carbon atoms, from 2 to 10,000 carbon atoms,from 3 to 10,000 carbon atoms, from 4 to 10,000 carbon atoms, from 5 to10,000 carbon atoms, from 6 to 10,000 carbon atoms, from 8 to 10,000carbon atoms, from 10 to 10,000 carbon atoms, from 15 to 10,000 carbonatoms, from 20 to 10,000 carbon atoms, from 25 to 10,000 carbon atoms,from 50 to 10,000 carbon atoms, from 100 to 10,000 carbon atoms, from250 to 10,000 carbon atoms, from 500 to 10,000 carbon atoms, from 2 to100 carbon atoms, from 3 to 30 carbon atoms, from 4 to 15 carbon atoms,or from 5 to 10 carbon atoms, such as 6 carbon atoms. R5 may compriseone or more heteroatoms, but some embodiments of R1 include only carbonand hydrogen.

In Chemical Structure #3, R6, R7, R8, R9, R10, R11, R12, and R13 may behydrogen atoms or hydrocarbons optionally comprising one or moreheteroatoms, respectively. For example, some of R6, R7, R8, R9, R10,R11, R12, and R13 may be structurally identical with one another andsome of R6, R7, R8, R9, R10, R11, R12, and R13 may be structurallydifferent from one another. For example, one or more of R6, R7, R8, R9,R10, R11, R12, and R13 may be hydrogen, or alkyl groups, such as methylgroups, ethyl groups, propyl groups, butyl groups, or pentyl groups. Inembodiments, one or more of R6, R7, R8, and R9 may be hydrogen. Inembodiments, one or more of R10, R11, R12, and R13 may be alkyl groups.For example, R10 may be a methyl, ethyl, propyl, or butyl group, and oneor more of R11, R12, and R13 may be methyl, ethyl, propyl, or butylgroups. In one embodiment, R10 is a methyl group and R11, R12, and R13are propyl groups. In one embodiment, R11, R12, and R13 are methylgroups. In another embodiment, R11, R12, and R13 are methyl groups. Inanother embodiment, R11, R12, and R13 are propyl groups.

In one or more embodiments, Chemical Structure #3 may be a polymer thatcomprises n monomer units, where n may be from 10 to 10,000,000 (such asfrom 50 to 10,000,000, from 100 to 10,000,000, from 250 to 10,000,000,from 500 to 10,000,000, from 1,000 to 10,000,000, from 5,000 to10,000,000, from 10,000 to 10,000,000, from 100,000 to 10,000,000, from1,000,000 to 10,000,000, from 10 to 1,000,000, from 10 to 100,000, from10 to 10,000, from 10 to 5,000, from 10 to 1,000, from 10 to 500, from10 to 250, or from 10 to 100. For example, n may be from 1,000 to1,000,000.

According to one or more embodiments, the cationic polymer comprisespoly(N¹,N¹-diallyl-N¹-alkyl-N⁶,N⁶,N⁶-trialkylalkane-1,6-diamoniumhalide), such aspoly(N¹,N¹-diallyl-N¹-methyl-N⁶,N⁶,N⁶-trialkylhexane-1,6-diamoniumbromide). An example of such ispoly(N¹,N¹-diallyl-N¹-methyl-N⁶,N⁶,N⁶-tripropylhexane-1,6-diamoniumbromide), referred to as (PDAMAB-TPHAB) and shown in Chemical Structure#4.

In another embodiment, the cationic polymer comprisespoly(N¹,N¹-diallyl-N¹-methyl-N⁶,N⁶,N⁶-triethylhexane-1,6-diamoniumbromide), referred to as (PDAMAB-TEHAB) and shown in Chemical Structure#5.

In another embodiment, the cationic polymer comprisespoly(N¹,N¹-diallyl-N¹-methyl-N⁶,N⁶,N⁶-trimethylhexane-1,6-diamoniumbromide), referred to as (PDAMAB-TMHAB) and shown in Chemical Structure#6.

The cationic polymers described in the present disclosure, includingthat of Chemical Structure #3, may be synthesized by a reaction pathwaysuch as that shown in FIG. 1. Specifically, FIG. 1 depicts a reactionpathway for the synthesis of PDAMAB-TPHAB. However, it should beunderstood that other reaction pathways may be utilized for thesynthesis of PDAMAB-TPHAB or other generalized polymers such as thepolymer of Chemical Structure #3. Furthermore, it should be understoodthat the reaction scheme depicted in FIG. 1 may be adapted to formpolymers which have a different structure than PDAMAB-TPHAB, such assome polymers included in the generalized Chemical Structure #3 (forexample, PDAMAB-TEHAB or PDAMAB-TEHAB. For example, the hydrocarbonchain length between the cation groups A and B of Chemical Structure #3may be changed by utilizing a different reactant in the scheme of FIG.1.

Referring to FIG. 1, the cationic polymer of Chemical Structure #3 maybe formed by a process comprising forming a diallyl methyl ammoniumhydrochloride cation with a chloride anion from diallylamine,polymerizing the diallyl methyl ammonium hydrochloride to form apoly(diallyl methyl ammonium hydrochloride) (PDMAH), forming apoly(diallyl methyl amine) (PDMA) from the poly(diallyl methyl ammoniumhydrochloride) (PDMAH), forming an ammonium halide cation with a halideanion by reacting a trialkyl amine, such as a tripropyl amine, with adihaloalkane, and forming the PDAMAB-TPHAB by reacting the PDMA with theammonium halide cation. In other embodiments, triethyl amine ortrimethyl amine may be utilized as the trialkyl amine.

Still referring to FIG. 1, according to one or more embodiments, thediallyl methyl ammonium hydrochloride cation with a chloride anion maybe formed by contacting the diallylamine with formic acid, formaldehyde,and HCl. In other embodiments, the diallyl methyl ammonium hydrochloridemay be polymerized by contact with 2,2′-axobis(2-methylpropionamidine)dihydrochloride (AAPH). In additional embodiments, the poly(diallylmethyl amine) (PDMA) may be formed by contacting the poly(diallyl methylammonium hydrochloride) (PDMAH) with methane and sodium methoxide.

According to another embodiment, the cationic polymer may be aco-polymer comprising the monomer of the structure depicted in ChemicalStructure #3 and the monomer of Chemical structure #7.

Referring to Chemical Structure #7, in one or more embodiments, A mayrepresent nitrogen or phosphorus. In one embodiment, A may be nitrogen,and in another embodiment, A may be phosphorus. For example, A ofChemical Structure #7 may comprise a quaternary ammonium cation or aquaternary phosphonium cation. As shown in Chemical Structure #7, A maybe a portion of a ring structure, such as a five sided ring. Anions maybe present and be attracted to A or B, or both, For example, anions maybe chosen from Cl⁻, Br⁻, F⁻, I⁻, OH⁻, ½SO₄ ²⁻, ⅓ PO₄ ³⁻, ½S²⁻, AlO₂ ⁻.In embodiments, an anion with a negative charge of more than 1-, such as2-, 3-, or 4-, may be present, and in those embodiments, a single anionmay pair with multiple cations of the cationic polymer.

In Chemical Structure #3, R6, R7, R8, R9, R10, may be hydrogen atoms orhydrocarbons optionally comprising one or more heteroatoms,respectively. For example, some of R6, R7, R8, R9, R10 may bestructurally identical with one another and some of R6, R7, R8, R9, R10may be structurally different from one another. For example, one or moreof R6, R7, R8, R9, R10, may be hydrogen, or alkyl groups, such as methylgroups, ethyl groups, propyl groups, butyl groups, or pentyl groups. Inembodiments, one or more of R6, R7, R8, and R9 may be hydrogen. Inembodiments, R10 may be an alkyl group. For example, R10 may be amethyl, ethyl, propyl, or butyl group. In one embodiment, R10 is amethyl group.

An embodiment of cationic polymers comprising the monomer of thestructure depicted in Chemical Structure #3 and the monomer of Chemicalstructure #7 is depicted in Chemical Structure #8.

As depicted in Chemical Structure #8, the co-polymer may include themonomeric component of Chemical Structure #3 in “m” parts and themonomeric component of Chemical structure #7 in “o” parts. According toembodiments, the ratio of m/(o+m) may be equal to from 0 to 100%. Forexample, when m/(o+m)=0%, the cationic polymer may include only themonomeric components depicted in Chemical Structure #7, and whenm/(o+m)=100%, the cationic polymer may include only the monomericcomponents depicted in Chemical Structure #3. In additional embodiments,m/(o+m) may be equal to from 0 to 25%, from 25% to 50%, from 50% to 75%,or from 75% to 100%. In some embodiments, m/(o+m) may be equal to from25% to 75%, or from 60% to 70%.

In one or more embodiments, Chemical Structure #7 may be a co-polymerthat comprises (o+m) monomer units, where (o+m) may be from 10 to10,000,000 (such as from 50 to 10,000,000, from 100 to 10,000,000, from250 to 10,000,000, from 500 to 10,000,000, from 1,000 to 10,000,000,from 5,000 to 10,000,000, from 10,000 to 10,000,000, from 100,000 to10,000,000, from 1,000,000 to 10,000,000, from 10 to 1,000,000, from 10to 100,000, from 10 to 10,000, from 10 to 5,000, from 10 to 1,000, from10 to 500, from 10 to 250, or from 10 to 100. For example, (o+m) may befrom 1,000 to 1,000,000.

Now referring to FIG. 1, the monomer of Chemical Structure #8 may, inone embodiment, be formed by supplying a lesser molar amount of ammoniumhalide cation, such that only a portion of the PDMA reacts with ammoniumhalide cation. In such an embodiment, the non-cation substituted PDMAmonomers are representative of the monomers of Chemical Structure #7 andthe cation substituted monomers are representative of the monomers ofChemical Structure #3.

According to one or more embodiments, the mesoporous zeolites describedin the present disclosure may be produced by utilizing the cationicpolymers described in the present disclosure as structure-directingagents. The mesoporous zeolites may comprise mesopores and micropores.The mesoporous zeolites described are generally silica-containingmaterials, such as aluminiosilicates, pure silicates, ortitanosilicates. The mesoporous zeolites may have surface areas and porevolumes greater than that of conventionally produced zeolites. In thisdisclosure, a “conventional zeolite” or “conventionally producedzeolite” refers to a zeolite that does not substantially comprisemesopores (for example, less than 0.5% of the zeolite pore volume ischaracterized as mesopores).

According to various embodiments, the mesoporous zeolites described inthe present disclosure may be produced by forming a mixture comprisingthe cationic polymer structure-directing agent (SDA), such asPDAMAB-TPHAB, and one or more precursor materials which will form thestructure of the mesoporous zeolites. The precursor materials maycontain the materials that form the porous structures, such as aluminaand silica for a aluminosilicate zeolite, titania and silica for atitanosilicate zeolite, and silica for a pure silica zeolite. Forexample, the precursor materials may be one or more of asilicon-containing material, a titanium-containing material, and analuminum-containing material. For example, at least NaAlO₂, tetra ethylorthosilicate, and the cationic polymer may be mixed in an aqueoussolution to form an intermediate material that will become a mesoporousaluminosilicate zeolite. It should be appreciated that other precursormaterials that include silica, titania, or alumina may be utilized. Forexample, in other embodiments, tetra ethyl orthosilicate and cationicpolymers may be combined to form an intermediate material that willbecome a silicate mesoporous zeolite; or tetra ethyl orthosilicate,tetrabutylorthotitanate, and cationic polymer may be combined to form anintermediate material that will become a titanosilicate mesoporouszeolite. Optionally, the combined mixture may be heated to form theintermediate material, and may crystallize under autoclave conditions.The intermediate material may comprise micropores, and the cationicpolymer may act as a structure-directing agent in the formation of themicropores during crystallization. The intermediate materials may stillcontain the cationic polymers which may at least partially define thespace of the mesopores following their removal. The products may becentrifuged, washed, and dried, and finally, the polymer may be removedby a calcination step. The calcination step may comprise heating attemperatures of at least about 400 degrees Celsius (° C.), 500° C., 550°C., or even greater. Without being bound by theory, it is believed thatthe removal of the polymers forms at least a portion of the mesopores ofthe mesoporous zeolite, where the mesopores are present in the spaceonce inhabited by the polymers.

The materials of the mixture determine the material composition of themesoporous zeolites, such as an aluminosilicate, a titanosilicate, or apure silicate. An aluminosilicate mesoporous zeolite may comprise amolar ratio of Si/Al of greater than or equal to 10 and less than10,000, greater than or equal to 25 and less than 10,000, greater thanor equal to 50 and less than 10,000, greater than or equal to 100 andless than 10,000, greater than or equal to 200 and less than 10,000,greater than or equal to 500 and less than 10,000, greater than or equalto 1,000 and less than 10,000, or even greater than or equal to 2,000and less than 10,000. In a pure silicate zeolite, a negligible amount orno amount of aluminum is present, and the Si/Al molar ratiotheoretically approaches infinity. As used herein a “pure silicate”refers to a material comprising at least about 99.9 weight percent (wt.%) of silicon and oxygen atoms. A pure silica mesoporous zeolite may beformed by utilizing only silicon-containing materials and no aluminum. Atitanosilicate porous structure may comprise a molar ratio of Si/Ti ofgreater than or equal to 30 and less than 10,000, greater than or equalto 40 and less than 10,000, greater than or equal to 50 and less than10,000, greater than or equal to 100 and less than 10,000, greater thanor equal to 200 and less than 10,000, greater than or equal to 500 andless than 10,000, greater than or equal to 1,000 and less than 10,000,or even greater than or equal to 2,000 and less than 10,000. It has beenfound that PDAMAB-TPHAB may be utilized to form mesoporous ZSM-5zeolites when used with silica and alumina precursor materials,mesoporous TS-1 zeolites when used with a silica and titania precursor,and mesoporous silicalite-I zeolites when used with silica precursors.It has also been found that PDAMAB-TMHAB may be utilized to formmesoporous Beta zeolites when used with silica and alumina precursors.

The formed mesoporous zeolites may comprise micropores characterized asMFI framework type, which is schematically depicted in FIG. 2. The MFIframework type comprises micropores which have a diameter of less thanor equal to 2 nm. However, other microporous zeolite structures, forexample, BEA, FAU, LTA framework types, are contemplated.

The formed mesoporous zeolites also comprise mesopores. It is believedthat the mesopores are formed from the voids created during calcinationof the polymers. The mesopores of the presently disclosed mesoporouszeolites may have an average size of from 4 nm to 16 nm, from 6 nm to 14nm, from 8 nm to 12 nm or from 9 nm to 11 nm. Conventionally preparedzeolites may have mesopores with a pore size of about 6 nm or less. Insome embodiments, the majority of the mesopores may be greater than 8nm, greater than 9 nm, or even greater than 10 nm. The mesopores of themesoporous zeolites described may range from 2 nm to 40 nm, and themedian pore size may be from 8 to 12 nm. In embodiments, the mesoporestructure of the mesoporous zeolites may be fibrous, where the mesoporesare channel-like. Without being bound by theory, it is believed that themesoporous zeolites disclosed have enhanced mesoporous characteristicsdue to the polymer structure of the SDA, which when calcined, leaves aplurality of interconnected channels in the mesoporous zeolite.

The mesoporous zeolites described in the present disclosure may haveenhanced catalytic activity. Without being bound by theory, it isbelieved that the microporous structures provide for the majority of thecatalytic functionality of the mesoporous zeolites described. The highmesoporosity allows for greater catalytic functionality because moremicropores are available for contact with the reactant in a catalyticreaction. The mesopores allow for better access to microporous catalyticsites on the mesoporous zeolite.

In embodiments, the mesoporous zeolites may have a surface area ofgreater than or equal to 300 m²/g, greater than or equal to 350 m²/g,greater than or equal to 400 m²/g, greater than or equal to 450 m²/g,greater than or equal to 500 m²/g, greater than or equal to 550 m²/g,greater than or equal to 600 m²/g, greater than or equal to 650 m²/g, oreven greater than or equal to 700 m²/g, and less than or equal to 1,000m²/g. In one or more other embodiments, the mesoporous zeolites may havepore volume of greater than or equal to 0.2 cm³/g, greater than or equalto 0.25 cm³/g, greater than or equal to 0.3 cm³/g, greater than or equalto 0.35 cm³/g, greater than or equal to 0.4 cm³/g, greater than or equalto 0.45 cm³/g, greater than or equal to 0.5 cm³/g, greater than or equalto 0.55 cm³/g, greater than or equal to 0.6 cm³/g, greater than or equalto 0.65 cm³/g, or even greater than or equal to 0.7 cm³/g, and less thanor equal to 1.5 cm³/g. In further embodiments, the portion of thesurface area contributed by mesopores may be greater than or equal to20%, greater than or equal to 25%, greater than or equal to 30%, greaterthan or equal to 35%, greater than or equal to 40%, greater than orequal to 45%, greater than or equal to 50%, greater than or equal to55%, greater than or equal to 60%, or even greater than or equal to 65%,such as between 20% and 70% of total surface area. In additionalembodiments, the portion of the pore volume contributed by mesopores maybe greater than or equal to 20%, greater than or equal to 30%, greaterthan or equal to 35%, greater than or equal to 40%, greater than orequal to 45%, greater than or equal to 50%, greater than or equal to55%, greater than or equal to 60%, greater than or equal to 65%, greaterthan or equal to 70%, or even greater than or equal to 75%, such asbetween 20% and 80% of total pore volume. Surface area and pore volumedistribution may be measured by N₂ adsorption isotherms performed at 77Kelvin (K) (such as with a Micrometrics ASAP 2020 system).

The mesoporous zeolites described may form as particles that may begenerally spherical in shape or irregular globular shaped (that is,non-spherical). In embodiments, the particles have a “particle size”measured as the greatest distance between two points located on a singlezeolite particle. For example, the particle size of a spherical particlewould be its diameter. In other shapes, the particle size is measured asthe distance between the two most distant points of the same particle,where these points may lie on outer surfaces of the particle. Theparticles may have a particle size from 25 nm to 500 nm, from 50 nm to400 nm, from 100 nm to 300 nm, or less than 900 nm, less than 800 nm,less than 700 nm, less than 600 nm, less than 500 nm, less than 400 nm,less than 300 nm, or less than 250 nm. Particle sizes may be visualexamination under a microscope.

The mesoporous zeolites described may be formed in a single-crystalstructure, or if not single crystal, may consist of a limited number ofcrystals, such as 2, 3, 4, or 5. The crystalline structure of themesoporous zeolites may have a branched, fibrous structure with highlyinterconnected intra-crystalline mesopores. Such structures may beadvantageous in applications where the structural integrity of thezeolite is important while the ordering of the mesopores is not.

According to another embodiment, mesoporous zeolites may be formed whichcomprises a core portion and a shell portion, where the shell portiongenerally surrounds the core portion. Such materials are described inthis disclosure as a “core/shell zeolite.” The core portion may be amesoporous zeolite comprising micropores, such as some conventionalzeolites, and may optionally comprise mesopores to some degree. Theshell portion comprises a mesoporous zeolite comprising mesopores andmicropores as previously described, and may be formed by utilizing thecationic polymer described in this disclosure as an SDA. In someembodiments, the core portion may comprise micropores, such as an MFIframework type, but not substantially comprise mesopores. In such anembodiment, the core portion may not substantially comprise mesopores,and the shell portion may comprise mesopores (or alternatively, theshell portion may comprise a higher degree of mesopores than the coreportion).

The core/shell zeolite may be produced by processes similar to theprocess for synthesizing the mesoporous zeolites comprising microporesand mesopores described previously. As described previously, suchmesoporous zeolites comprising micropores and mesopores may befabricated by utilizing a cationic polymer, such as the polymer ofChemical Structure #3 or the polymer of Chemical Structure #8. To formthe core/shell zeolite embodiment, a seed material, which will becomethe core portion, is added to the mixture comprising the SDA polymer andthe precursor materials. The seed material may be a pre-fabricatedzeolite which works as a crystalline seed upon which mesoporous zeolite(containing mesopores and micropores) is grown. The mesoporous zeoliteis formed around the seeds, and the core/shell structure is formed. Forexample, a crystallized intermediate material may be formed around thecore which includes micropores, and in a subsequent step, the polymer isremoved by calcination to produce mesopores.

The core portion, which may have the same composition and microporousstructure as the seed material, may comprise a zeolite such as an MFIframework type zeolite, for example, a ZSM-5 zeolite. However, the coreportion may comprise other materials such as silicate zeolites andtitanosilicate zeolites, or zeolites with different microporousframework types, such as Y-zeolites. The seed materials may have alength of from 25 nm to 500 nm, such as from 50 nm to 300 nm, or from 75nm to 200 nm. The size of the seed materials determines the size of thecore portion of the core/shell zeolite.

The shell portion may have a composition and structure of the mesoporouszeolites described previously in the present disclosure. For example,the surface area, pore volume, and materials of composition of theMFI-structured or BEA-structured, mesoporous zeolites previouslydescribed may be the same as those of the shell material. Without beingbound by theory, it is believed that the materials of the shell portionand the core portion are interconnected at the interface of the twomaterials by Si—O—Si covalent bonds. The shell portion may have athickness of from 10 nm to 300 nm, such as 20 nm to 200 nm, from 20 nmto 50 nm, from 50 nm to 100 nm, from 100 nm to 150 nm, or from 150 nm to200 nm. Generally, the thickness of the shell portion can be variedbased on the amount of seeds that are added to the mixture, as lessseeds may produce thicker shells, and more seeds may produce thinnershells.

In some embodiments, the core and shell have the same microstructure,which may allow for the formation of a single-crystalline core/shellbody. If the core and shell have different microstructures, the shellmay grow at defective sites on the outer surface of the core. However,matching of the microstructure framework of the core and shell materialmay produce enhanced core/shell embodiments. In some embodiments, thecore/shell structure is at least partially enhanced by matching offramework type of the core and shell zeolites.

In one or more embodiments, non-surfactant polymer-based templates arenot limited to the creation of interconnecting mesopores in zeolitecrystals. For example, different from small molecules, polymer chainscan be easily grafted with functional groups. It is contemplated that ifa polymer containing additional functional groups besides the SDA groupsis used to synthesize zeolites, the corresponding functionalities (forexample, adsorption capacity, catalytic activity, molecular recognitionability, fluorescent property) can be “carried” into the resultinghierarchical zeolites to render multi-functional materials. For example,direct incorporation of colloidal nanocrystals may be achieved, such asmetal or oxide nanocrystals, into hierarchical zeolite particles duringthe synthesis, by functionalizing the polymer template with specialgroups that have specific interaction with the nanocrystals. Forexample, PDAMAB-TPHAB has a high density of quaternary ammonium groupsalong the polymer chain, a small fraction of which play the role of SDAfor the crystallization of ZSM-5, leaving a large number of unusedammonium groups. These reductant ammoniums may be available asadsorption sites to adsorb anions.

The mesoporous zeolites described in the present disclosure can beapplied to many industrially valuable processes. These processes includefluidization processes (such as fluidized catalytic cracking (FCC), deepcatalytic cracking (DCC), and high severity fluidized catalytic cracking(HSFCC)), dehydrogenation process, isomerization process, methanol toolefin process (MTO) and reforming process. Table 1 summarizes someindustrial applications of zeolites and other porous catalytic materialsin the petrochemical industry. The present mesoporous zeolites andcore/shell structures may replace these catalysts or be used incombination with these catalysts.

Additionally, core/shell embodiments may be particularly suited forfacilitating the conjugation of zeolite with polymer to fabricatehigh-quality composite membranes without interfacial defects forseparation or catalysis, where molecules can be pre-aligned by themesopores in the shell before they enter the microporous core, givingunusual transportation properties. The shell and the core with differentcatalytic activities may form a tandem catalyst for multistep reactions.

TABLE 1 Zeolitic Catalytic Reaction Target Description Catalyst FluidCatalytic cracking To convert high boiling, high molecular REY, USY,mass hydrocarbon fractions to more ZSM-5 valuable gasoline, olefinicgases, and other products Hydrocracking To produce gasoline with higherquality NiMo or NiW/USY Hydrodesulfurization (HDS) To produce clean,high quality fuels and Pt, Pd, Ru, Ir, feeds for petrochemical industryNi loaded on a HY zeolite Gas oil hydrotreating/Lube Maximizingproduction of premium Ni, W or Pt/Y hydrotreating distillate bycatalytic dewaxing or ZSM-5 Alkane cracking and alkylation To improveoctane and production of ZSM-5 of aromatics gasolines and BTX Olefinoligomerization To convert light olefins to gasoline & Pt/FRR ZSMdistillate Methanol dehydration to To produce light olefins frommethanol SAPO-34, olefins ZSM-5 Heavy aromatics To produce xylene fromC9+ ZSM-5, Y, 6, transalkylation Fischer-Tropsch Synthesis FT To producegasoline, hydrocarbons, and Co/Al2O3 and linear alpha-olefins, mixtureof oxygenates H-ZSM-5 CO2 to fuels and chemicals To make organicchemicals, materials, and g-Al₂O₃, carbohydrates HZSM-5, and NaHZSM-5

EXAMPLES

The various embodiments of methods and systems for forming mesoporouszeolites and core/shell zeolites will be further clarified by thefollowing examples. The examples are illustrative in nature, and shouldnot be understood to limit the subject matter of the present disclosure.

Throughout the various examples, powder X-ray diffraction (XRD) patternswere recorded on a Bruker D8 Advance diffractometer using Cu Kαradiation. Inductively coupled plasma-optical emission spectroscopy(ICP-OES) was conducted on a Varian 720-ES spectrometer.Thermogravimetric analysis (TGA) was performed on a Netzsch TG 209 F1apparatus under flowing air at a rate of 25 milliliters per minute(mL/min) and a constant ramping rate of 10 Kelvin per minute (K/min). N₂adsorption-desorption isotherms were collected on a Micromeritics ASAP2420 analyzer at 77 K. Temperature-programed desorption (TPD)measurements using NH₃ as the probe molecule were performed on aMicromeritics AutoChem II 2950 apparatus. Before measurements, 0.15 g ofthe sample was pretreated in He gas (25 mL/min) for 1 hour at 500° C.and then cooled to 100° C. Next, the sample was exposed to a mixed gas(10 mole percent (mol %) NH₃ and 90 mol % He) flow of 20 mL/min for 1hour to ensure the sufficient adsorption of NH₃. Prior to desorption,the sample was flushed in He gas for 3 h. Subsequently, NH₃ desorptionwas performed in the range of 100-600° C. at a heating rate of 10degrees Celsius per minute (° C./min) under a He flow of 20 mL/min.Electron microscopy imaging and tomography was carried out on FEI-TitanST electron microscope operated at 300 kilovolt (kV), except the imageshown in FIG. 19C, which was taken at a JEOL JEM-3010 microscopeoperated at 300 kV. For TEM tomography, an electron tomography tiltseries from 75 degrees (°) to 75° at 1° intervals was firstly alignedand then reconstructed to a 3D volume using the SIRT function in the FEIInspect 3D software. The 3D volume rendering, density segmentation andslicing were then achieved by the Avizo software.

Example 1—Synthesis of PDAMAB-TPHAB Cationic Polymer

A generalized reaction sequence for producing PDAMAB-TPHAB is depictedin FIG. 1. Each step in the synthesis is described in the context ofFIG. 1.

In a first step, a methyl amine monomer was synthesized. Diallylamine (1part equivalent, 0.1 mol) was slowly added to a solution of formic acid(5 equivalent, 0.5 mol) that was cooled to 0° C. in a 500 milliliter(mL) round-bottom flask. To the resulting clear solution a formaldehydesolution (37% solution; 3 equivalent, 0.3 mol) was added and the mixturewas stirred at room temperature for 1 hour. Then, the flask wasconnected to a reflux condenser and the reaction mixture was heatedovernight at 110° C. After, the solution was cooled and aqueous HCl (4N, 2 equivalent, 0.9 mol, 225 mL) was added. The crude reaction productwas evaporated to dryness under reduced pressure.

In a second step, a poly(diallyl methyl amine) (PDMA) was synthesized. A50% aqueous solution of the monomer diallyl methyl ammoniumhydrochloride with 3.2% initiator of 2,2′-azobis(2-methylpropionamidine)dihydrochloride (AAPH) was purged with nitrogen for 20 minutes (min).Afterwards, the reaction was stirred under nitrogen atmosphere at 50° C.for 3 hours, and then the reaction was increased to 60° C. for another 6hours. The product poly(diallyl methyl ammonium hydrochloride) (PDMAH)was purified by dialysis and the water was removed on the rotaryevaporator under reduced pressure. Then, the PDMAH (1 part equivalentwith respect to monomer unit) was dissolved in a minimum amount ofmethanol and placed in an ice bath. Subsequently, sodium methoxide (1part equivalent) dissolved in a minimum amount of methanol, was added.The reaction was stored in a freezer for 1 hour. The PDMA methanolsolution was obtained after removing the NaCl with centrifugation.

In a third step, 6-bromo-N,N,N-tripropylhexan-1-aminium bromide (BTPAB)was synthesized. A tripropyl amine (0.05 mol)/toluene mixture (1:1volume/volume (v/v)) was added to 1,6-dibromohexane (0.1mol)/acetonitrile (1:1 v/v) slowly at 60° C. under magnetic stirring,and kept at this temperature for 24 hours. After cooling to roomtemperature and solvent evaporation, the obtained BTPAB was extractedthrough a diethyl ether—water system that separates excess1,6-dibromohexane from the mixture.

In a fourth step, PDAMAB-TPHAB was synthesized. For the synthesis ofPDAMAB-TPHAB, 1 part equivalent of PDMA (with respect to monomer unit)in methanol was dissolved with 1 part equivalent of BTPAB inacetonitrile/toluene (40 mL, v:v=1:1) and refluxed at 70° C. for 72hours under magnetic stirring. After cooling to room temperature andthen solvent evaporation, the obtained PDAMAB-TPHAB was further purifiedby dialysis method in water.

Example 2—H-NMR Analysis of PDAMAB-TPHAB Cationic Polymer

The PDAMAB-TPHAB polymer synthesized in Example 1 was analyzed by H-NMR.The H-NMR spectrum for the polymer produced in Example 1 is depicted inFIG. 3. The H-NMR spectrum shows peaks at or near 0.85 parts per million(ppm), at or near 1.3 ppm, at or near 1.6 ppm, at or near 2.8 ppm, andat or near 3.05 ppm.

Example 3—Synthesis of Mesoporous ZSM-5 Zeolite with 100 Si/Al Ratio

A mesoporous ZSM-5 zeolite was formed having a Si/Al molar ratio of 100.First, 0.1093 grams (g) of NaAlO₂ and 0.2 g NaOH was dissolved in 14.4mL of water with stirring for 0.5 hours. When a clear solution wasformed, 0.497 g of PDAMAB-TPHAB was added to the solution and stirredfor 0.5 hours. Then, 4.16 g of tetraethyl orthosilicate was added at 60°C. The molar composition of the mixture was 1 PDAMAB-TPHAB: 20 SiO₂: 2.5Na₂O: 0.1 Al₂O₃: 800 H₂O. After stirring for 10 hours at 60° C., theresulting gel was heated to 100° C. for an additional 2 hours.Crystallization was conducted in Teflon-lined stainless steel autoclaves(sized 25 mL) at 150° C. for 48 hours. The products were centrifuged,washed with distilled water and methanol, and dried at 100° C.overnight. The polymer template was removed from the as-synthesizedmaterial by calcination at 550° C. for 5 hours.

Example 4—Synthesis of Mesoporous TS-1 Zeolite with 60 Si/Ti Ratio

A mesoporous titanosilicate zeolite was formed having a Si/Ti molarratio of 60. First, 0.2 g NaOH was dissolved in 14.4 mL of water withstirring for 10 minutes. When a clear solution was formed, 0.497 g ofPDAMAB-TPHAB was added to the solution and stirred for 0.5 hours. Then,a mixture of tetraethylorthosilicate and tetrabutylorthotitanate (totalamounts: 4.16 g) with Si/Ti molar ratio 60 was added at 60° C. The molarcomposition of the mixture was 1 PDAMAB-TPHAB: 20 SiO₂: 0.33 TiO₂: 2.5Na₂O: 800H₂O. After stirring for 10 hours at 60° C., the resulting gelwas heat to 100° C. for an additional 2 hours. Crystallization wasconducted in Teflon-lined stainless steel autoclaves (sized 25 mL) at150° C. for 48 hours. The products were centrifuged, washed withdistilled water and methanol and, dried at 100° C. overnight. Thepolymer template was removed from the as-synthesized material bycalcination at 550° C. for 5 hours.

Example 5—Analysis of Mesoporous ZSM-5 Zeolite with 100 Si/Al Ratio

The mesoporous ZSM-5 zeolite of Example 3 was analyzed. FIG. 5 depictsX-ray diffraction (XRD) patterns of the mesoporous ZSM-5 zeoliteas-synthesized and following calcination. It was determined from the XRDpatterns that the zeolite of Example 3 had an MFI type of zeolitestructure, which was well maintained after the removal of polymertemplate by calcination. For example XRD peaks at those shown in FIG. 5were used to determine that the zeolite had an MFI framework typemicrostructure.

Additionally, the mesoporous ZSM-5 zeolite of Example 3 was tested forporosity. FIG. 5 depicts N₂ sorption isotherms for the zeolite ofExample 3 and a conventionally prepared ZSM-5 zeolite, and indicatesthat it has a much higher porosity than does a conventional ZSM-5zeolite. A surface area of 700 m²/g was measured for the zeolite ofExample 3, as opposed to a surface area of 320 m²/g for a conventionalZSM-5 zeolite. Additionally, a total pore volume of 0.71 cm³/g wasmeasured for the zeolite of Example 3, as opposed to a total pore volumeof 0.23 cm³/g for a conventional ZSM-5 zeolite. In the zeolite ofExample 3, 57% of the total surface area and 68% of the total porevolume are contributed by mesopores. Additionally, FIG. 6 depicts thedistribution curve of mesopores in the zeolite of Example 3. Themesopores have a relatively broad size distribution, centered at or near10 nm, as shown in FIG. 6.

Referring to FIG. 7, a transmission electron microscope (TEM) image ofthe zeolite of Example 3 is depicted. The TEM characterization showsthat the zeolite of Example 3 consists of uniform and relatively small(about 200 nm in size) but highly mesoporous particles. Further, FIG. 8depicts a high resolution transmission electron microscope image (HRTEM)of the zeolite of Example 3, FIG. 9 depicts a Fast Fourier Transform(FFT) image of the selected area shown in FIG. 8, and FIG. 10 depicts adark field scanning electron microscope (STEM) image of the zeolite ofExample 3. The high crystallinity of these particles are confirmed withthe HRTEM images, while the FFT of the HRTEM image suggests that eachparticle is of a single-crystalline nature despite the presence of asignificant amount of mesopores. The HRTEM image of FIG. 8 also revealthat the zeolite of Example 3 particles are highly branched, and eachbranch is only 3 to 4 nm in thickness, corresponding to 1 to 2 unitcells. The STEM image of FIG. 10 show the mesoporous structure in theparticle more clearly due to the better image contrast.

Example 6—Analysis of Mesoporous ZSM-5 Zeolites with Si/Al Molar Ratioof 31

A mesoporous ZSM-5 zeolite with a Si/Al molar ratio of 31 was preparedin a process similar to Example 3 (with a different ratio of Si to Alprecursor materials), which had a measured surface area of 655.6 m²/g, ameasured total pore volume of 0.66 cm³/g, and a measured microporevolume of 0.081 cm³/g. FIG. 19A-19D depicts images of the 31 molar ratioSi/Al mesoporous ZSM-5 zeolite. Specifically, FIG. 19A depicts alow-magnification TEM image. FIG. 19B depicts the ED pattern and TEMimage of a single mesoporous ZSM-5 particle. The ED pattern can beindexed as two sets of [010]-projected reflections with an in-planeorientation difference of about 35 degrees. FIG. 19C depicts ahigh-resolution TEM image taken along the [010] direction at theperiphery of a mesoporous ZSM-5 particle, showing the fibrous structurewith ordered arrangement of 10-ring channels. The thinnest region (about3.5 nm) in the fiber is indicated, along with a structural model forcomparison. The inset at the left bottom corner is the correspondinglow-magnification TEM image, in which the region for HRTEM imaging islabeled. FIG. 19D depicts a reconstructed electron tomographic volume ofa mesoporous ZSM-5 particle, and three slices intersected at differentregions of the volume. The slices are rendered in a rainbow colorscheme, where empty areas are deep blue. In slices II and III, thediscrete dots, some of which are indicated by arrows, representcross-sections of protruding fibers. Scale bars represent 50 nm.

The mesoporous ZSM-5 zeolite having an Si/Al molar ratio of 31 wascompared with conventional ZSM-5 zeolites. Two conventional ZSM-5zeolites were prepared. A “nano ZSM-5 conventional zeolite” was preparedhaving an average particle size of about 200 nm (using atetrapropylammonium hydroxide (TPAOH) polymer as the SDA), which had anSi/Al molar ratio of 26, a measured surface area of 399.1 m²/g, ameasured total pore volume of 0.24 cm³/g, and a measured microporevolume of 0.099 cm³/g. Also, a “micro ZSM-5 conventional zeolite” wasprepared having an average particle size of 3-10 microns (μm)(commercially available from the Catalyst Plant of Nakai University),which had a an Si/Al molar ratio of 25, a measured surface area of 298.6m²/g, a measured total pore volume of 0.15 cm³/g, and a measuredmicropore volume of 0.092 cm³/g. FIGS. 20A-20D show various distinctionsbetween the conventional ZSM-5 zeolites and the mesoporous ZSM-5zeolites. FIG. 24A depicts a TEM image of nano ZSM-5 conventionalzeolite and FIG. 24B depicts a TEM image of micro ZSM-5 conventionalzeolite.

FIG. 20A depicts powder X-ray diffraction patterns for mesoporous ZSM-5zeolite and micro ZSM-5 conventional zeolite. FIG. 20B depicts N₂adsorption-desorption isotherms for mesoporous ZSM-5 zeolite and microZSM-5 conventional zeolite. FIG. 20C depicts thermogravimetric analysisprofiles for mesoporous ZSM-5 zeolite and nano ZSM-5 conventionalzeolite. FIG. 20D depicts NH₃-TPD profiles for mesoporous ZSM-5 zeoliteand micro ZSM-5 conventional zeolite.

Transmission electron microscopy (TEM) shows that the mesoporous ZSM-5zeolite consists of relatively uniform particles in sizes of 200-250 nm,and that most particles have elongated shapes. The broadened X-raydiffraction (XRD) peaks of mesoporous ZSM-5 zeolite relative toconventional ZSM-5 zeolites suggest that the former has smallercrystallite sizes, in accordance with its porous structure at mesoscaleas revealed by TEM. There are no concomitant impurity phases oramorphous components observed in mesoporous ZSM-5 zeolite by TEM andXRD. The presence of high mesoporosity in mesoporous ZSM-5 zeolite isconfirmed by the adsorption isotherm, in which the continuous increaseof the adsorbed volume with the relative pressure in the range ofP/P₀>0.10 indicates a highly open and interconnected mesoporous system.Accordingly, mesoporous ZSM-5 zeolite has a significantly larger BETsurface area (655 m²/g versus 298 m²/g) and total pore volume (0.66cm³/g versus 0.15 cm³/g) than does conventional ZSM-5. Thermogravimetricanalysis of as-synthesized mesoporous ZSM-5 zeolite showed a markedweight loss (>40 wt. %) in the region of 200-650° C., corresponding tothe decomposition of PDAMAB-TPHAB. By comparison, conventional ZSM-5zeolite synthesized using tetrapropylammonium hydroxide as a SDA showeda weight loss of about 15 wt. % in the same range temperature range.This result confirms the incorporation of PDAMAB-TPHAB in mesoporousZSM-5 zeolite and its role of a “porogen” to generate mesopores.

According to one or more embodiments, the molecule weight ofPDAMAB-TPHAB has little influence on the textural properties ofmesoporous ZSM-5 zeolite. FIG. 28 shows an N₂ adsorption isotherm of amesoporous ZSM-5 zeolite sample synthesized using PDAMAB-TPHAB with asmaller molecular weight than that used for the synthesis describedpreviously (about 130 K versus about 390 K). Two PDAMAB-TPHAB sampleswere synthesized with different molecular weights by controlling thetemperature and reaction time of the polymerization process. It isdifficult to accurately determine their molecular weights by gelpermeation chromatography. Therefore, their intrinsic viscosity weremeasured with the Cannon Unnelohde viscometer at 30° C. by following anestablished method (A. L. Prajapat, P. R. Gogate/Chemical Engineeringand Processing, 2015, 88, 1). Using poly dimethyl diallyl ammoniumchloride with molecular weights from 100 kilodaltons (kDa) to 200 kDaand 400 kDa to 500 kDa as references, we roughly determined the averagemolecular weights of the two PDAMAB-TPHAB samples to be 390 kDa and 130kDA, respectively. The former was used for all the synthesis of MFI-typehierarchical zeolites described in this disclosure, while the latter wasused only here for comparison purposes.

FIG. 19B presents the TEM image and electron diffraction (ED) pattern ofa typical mesoporous ZSM-5 zeolite particle. The ED pattern contains twosets of [100]-projected reflections, suggesting that this particle iscomprised of two single crystals with their a axes aligned and anorientation difference of about 35 degrees in the be plane. Notably,some mesoporous ZSM-5 zeolite particles are thinner and more a TEM imageof a mesoporous ZSM-5 zeolite particle and the corresponding ED patternelongated than the rest, as labeled with white arrows in FIG. 19A. TEMand ED results shown in FIG. 29 show that such a particle is essentiallya single crystal and that the elongation is along the c-axis.Specifically, FIG. 29 shows and FFT of the mesoporous ZSM-5 zeoliteparticle, regarding FIG. 29, it should be noted that the [010] and the[100] projections cannot be distinguished at the current resolution, andthat [010] was arbitrarily chosen for indexing. Also, mesoporous ZSM-5zeolite may have ultra-thin “fibers” at particle periphery protrudingalong the elongation directions. High-resolution TEM clearly showsordered 10-ring microporous channels in the fibers, and confirms thatthe fibers are grown along the c-axis, as shown in FIG. 19C. Thethinnest region of the fibers is about 3.5 nm, containing only three10-ring channel layers, as shown in FIG. 19C. When tilting the TEMspecimen within a large angle range, it was found that the fibersretained their one-dimensional (1-D) morphology. For example, FIGS.30A-30D shows TEM images of protruding MFI fibers taken at differentincident angles (i.e.: −40° in FIG. 30A, −20° in FIG. 30B, 0° in FIG.30C, and 20° in FIG. 30D), by tilting the TEM specimen. The fibersretain their 1-D morphologies during the titling, ruling out thepossibility that these “fibers” are lateral projections of 2-Dnanosheets. Also, TEM tomography was performed to characterizemesoporous ZSM-5 zeolite. FIG. 19D presents a reconstructed electrontomographic volume of a mesoporous ZSM-5 zeolite particle and threeslices (about 2 nm thick) intersected at different regions of thevolume. In the central area of the particle, as shown in slice I,disordered mesopores are encompassed by a continuous zeolite framework.Meanwhile, zeolite exhibits highly branched fibrous structures to formlarger and more open mesopores at the periphery of the particle, asdemonstrated in slices II and III, where the discrete dots represent thecross-sections of the protruding fibers, shown in FIG. 19D.

According to electron microscopy and tomography, the structural featuresof mesoporous ZSM-5 zeolite may be characterized as follows: despitebeing highly mesoporous, most mesoporous ZSM-5 zeolite particles aresingle crystals or composed of two intergrown single crystals. Eachsingle crystal is slightly elongated along the c-axis with branchedultrathin fibers at the two ends. A small number of particles lookthicker and more round compared to the majority (for example, particleslabeled by black arrows in FIG. 19A, because they contain more (that is,at least 2) staggered single crystals. FIG. 31 shows a simplifiedschematic illustration of mesoporous ZSM-5 zeolite with one or morestaggered crystal structures. Specifically, FIG. 34 shows simplifiedschematic illustrations of mesoporous ZSM-5 zeolites, where the far leftrepresents a single-crystalline mesoporous elongated (along the c-axis)ZSM-5 particle, which can exist alone or in combination with one (or afew) more particles in staggered configurations through intergrowth, asillustrated in the right three schemes of FIG. 31. Thesingle-crystalline nature distinguishes mesoporous ZSM-5 zeolite fromsurfactant-templated zeolites, which are constructed by 2-D zeolitenanosheets or random agglomeration of small (several nm) zeolite grains.

Example 7—Synthesis and Analysis of Mesoporous Silicalite-I

The procedure of Example 3 was used to produce silicalite mesoporousstructures by not including aluminum in the mixture. FIG. 12 depicts anHRTEM image of the silicalite produced. The mesoporous Silicalite-Izeolite had a measured surface area of 671.4 m²/g, a measured total porevolume of 0.77 cm³/g, and a measured micropore volume of 0.080 cm³/g.

Example 8—Analysis of Mesoporous TS-1

The mesoporous titanosilicate material of Example 4 was analyzed. FIG.13 depicts a TEM image of the titanosilicate material of Example 4, andFIG. 14 depicts an XRD pattern of the titanosilicate material of Example4. The mesoporous TS-1 zeolite had had a measured surface area of 527m²/g, a measured total pore volume of 0.61 cm³/g, and a measuredmicropore volume of 0.065 cm³/g.

Example 9—Synthesis of Zeolite Core/Mesoporous Zeolite Shell Structures(Core/Shell Zeolites)

A core/shell zeolite structure was formed. First, 0.1-0.5 g ofpre-synthesized zeolite crystals (for example, ZSM-5, Y, or Beta) weredispersed in 6.3 g of water to make a suspension. Then, PDAMAB-TPHAB(0.2485 g), sodium aluminate (0.0164 g) and 10% NaOH aqueous solution (1g) were added to the suspension. After stirring for 6 h, 2.229 mL TEOSwas added and stirred for another 4 h. The resulting gel was heated to100° C. for 1 h. Crystallization was conducted in Teflon-lined stainlesssteel autoclaves (25 mL) at 150° C. for 48 h. The products werecentrifuged, washed with distilled water and methanol, and dried at 100°C. overnight. The polymer template was removed from the as-synthesizedmaterial by calcination at 550° C. for 5 h.

Depending on the type of the zeolite seeds, different core-shellstructures could be synthesized using this method. Depending on theamount of zeolite seeds used, the thickness of mesoporous zeolite shellcould be tuned from about 20 nm to about 200 nm. Samples were preparedutilizing conventional ZSM-5 core materials and conventional Y zeolitecore materials, each with mesoporous ZSM-5 shells. HRTEM demonstratedthe complete crystallinity and mesoporosity of the shell, as well ashighly coherent interfaces between the core and the shell, revealing aepitaxial relationship. Strain mappings by geometric phase analysisconfirmed the coherent interfaces with small strains, and revealed theexistence of considerable strain fluctuations at the shell region as aconsequence of adapting mesopores. ED and fast Furrier transform (FFT)of the HRTEM images indicated that the crystal remainedsingle-crystalline after the growth of mesoporous ZSM-5 shell (the seedcrystals were single-crystalline). These results confirm again thatnon-surfactant polymers enable the formation of mesoporous yetsingle-crystalline zeolite structures.

Additionally, combinations of core and shell materials such asconventional TS-1 core/meso ZSM-5 shell, conventional ZSM-5core/mesoporous TS-1 shell, conventional TS-1 core/mesoporous TS-1shell, conventional Silicalite-1 core/mesoporous ZSM-5 shell, andconventional ZSM-5 core/mesoporous Silicalite-1 shell, can besynthesized by varying the seeds, the synthetic precursors or both. Ifthe core and shell have the same microporous framework, the core/shellcan be constructed from a single crystal, where the shell portion isepitaxially grown from the seed portion (that is, the core).

FIGS. 26A-26E shows images of core/shell structures prepared from nanoZSM-5 conventional zeolite core materials/seeds and mesoporous ZSM-5zeolite shells. FIG. 29A shows a TEM image of a core/shell structurewith a relatively thin shell and FIG. 26B shows a TEM image of acore/shell structure with a relatively thick shell. FIG. 26C shows thereconstructed core/shell particle by TEM tomography viewed in twoorthogonal directions, where the mesoporous shells are labeled in asemitransparent manner to display the core crystal. FIG. 26C shows aHR-TEM image and FIG. 26D shows the corresponding FFT (left) and EDpattern (right) of the core/shell particle, showing a porous yetcrystalline shell and its perfect epitaxial relationship with the corecrystal. FIG. 26E shows the distribution of different strain components(ε_(xx), ε_(yy), ε_(xy), and r_(xy); cutoff at ±15%) determined bygeometric phase analysis, showing a highly coherent (less strained)core-shell interface and the presence of strains in the outmost shell.

FIGS. 32A-32D shows SEM images, XRD data, and N₂ adsorption isothermsfor core/shell structures prepared from nano ZSM-5 conventional zeolitecore materials and mesoporous ZSM-5 zeolite shells having varying shellthickness. Specifically, FIG. 32A shows a low-magnification TEM image ofZSM-5/mesoporous ZSM-5 core/shell particles with thinner shells, FIG.32B shows a low-magnification TEM image of ZSM-5/mesoporous ZSM-5core/shell particles with thicker shells, FIG. 32C shows XRD patternsand FIG. 32D shows N₂ adsorption isotherms, respectively, ofZSM-5/mesoporous ZSM-5 core/shell zeolites with different shellthicknesses and the bulk ZSM-5 seeds (nano ZSM-5 conventional zeolite).The results show the coherency between the core and the shell instructure, and the increase of mesoporosity with increasing thethickness of the shell.

Example 10—Analysis of Core/Shell Zeolites

The core/shell zeolites of Example 9 were analyzed by TEM imaging. FIGS.15A-15D depict TEM images of ZSM-5 core/mesoporous ZSM-5 shell porousstructures where FIG. 15A depicts the core (that is, the seed)materials, FIG. 15B depicts a core/shell structure with a shellthickness of about 40 nm, FIG. 15C depicts a core/shell structure with ashell thickness of about 100 nm, and FIG. 15D depicts a core/shellstructure with a shell thickness of about 150 nm. FIGS. 16A and 16Bdepict TEM images of Y zeolite core/mesoporous ZSM-5 shell porousstructures, where the image of FIG. 16A is of zeolite Y seed materialsand the image of FIG. 16B is of the core/shell zeolite.

FIGS. 33A and 33B show TEM images of “dimers” comprised of mesoporousZSM-5 zeolite grown on bulk conventional zeolite Beta crystals. Thesematerials were obtained when it was attempted to grow a mesoporous ZSM-5layer on the surface of conventional zeolite Beta crystals. Theseresults suggest the lattice matching between the seed and the growingmaterial may be crucial in some embodiments for forming a core/shellstructure.

Example 11—Fabrication and Analysis of Mesoporous Beta Zeolites

To produce a mesoporous Beta zeolite, 0.058 g of NaAlO₂, 0.4 g of NaOH,and 0.41 g of PDAMAB-TMHAB were added to 14.4 mL of de-ionized water.After stirring for 1 hour, 0.935 g of fumed silica was added to thesolution. The resulting gel (composition in molar: 1 PDAMAB-TMHAB: 15.6SiO₂: 5 Na₂O: 0.35 Al₂O₃: 800 H₂O) was transfer into an autoclave after12 h. The crystallization was carried out at 180° C. for 96 hours. Theobtained powder was collected by centrifugation and washed by water andmethanol for several times. After 24 hours drying at 80° C. undervacuum, the polymer template was removed by calcining at 550° C. for 6hours. The Si/Al ratio of the as-synthesized mesoporous Beta zeolite was20.

FIG. 17A shows TEM images of hierarchically structured mesoporous Betazeolites at different magnifications; FIG. 17B shows XRD patterns of themesoporous Beta zeolites and conventional beta zeolite, marked “bulkBeta” in the figure; and FIG. 17C shows N₂ sorption isotherms of themesoporous Beta zeolites and conventional bulk beta zeolite. Themesoporous Beta zeolites has a surface area of 750 m²/g and a total porevolume of 1.1 cm³/g; in contrast, and conventional (microporous) Betazeolite has a surface area of 550 m²/g and a total pore volume of 0.3cm³/g.

Another mesoporous Beta zeolite was fabricated having a Si/Al ratio of18, which had a measured surface area of 616 m²/g, a measured total porevolume of 1.01 cm³/g, and a measured micropore volume of 0.151 cm³/g.

In comparison, the conventional Beta zeolite was prepared fromtetraethylammonium hydroxide (TEAOH) as an SDA with a Si/Al molar ratioof 15. The convention Beta zeolite had a measured surface area of 633.5m²/g, a measured total pore volume of 0.27 cm³/g, and a measuredmicropore volume of 0.214 cm³/g.

Example 12—Fabrication of Beta Core/Mesoporous Beta Shell Zeolites

Beta Core/mesoporous Beta shell zeolites were synthesized through seededgrowth by using pre-synthesized conventional (microporous) Beta zeolitecrystals as seeds. The shell synthesis procedure is identical to thatfor the zeolites of Example 11 described previously, except that 20-50wt. % (relative to fumed silica) pre-synthesized conventional zeoliteBeta was added into the precursor. FIGS. 18A and 18B depict TEM imagesof Beta core/mesoporous Beta shell zeolites at different magnifications.FIGS. 27A and 27B also show images of Beta Core/mesoporous Beta shellzeolites. FIG. 27A shows low-magnification TEM images of BetaCore/mesoporous Beta shell zeolites and zeolite Beta seeds (inset). FIG.27B shows a TEM image of a single Beta Core/mesoporous Beta shellzeolite particle. The corresponding ED pattern (inset) indicates thesingle-crystalline nature of the particle, and the elongated reflectionsimply the presence of strains associated with mesopores. FIGS. 27C and27D show HR-TEM images of Beta Core/mesoporous Beta shell zeolites takenat particle peripheries as labeled in FIG. 27B, showing coherentcore-shell interfaces and the high crystallinity of the shell.

Example 13—Analysis of Mesoporous ZSM-5 Zeolites with Varying Si/AlMolar Ratios

The procedure of Example 3 was used to produce zeolites with varyingmolar ratios of Si to Al. FIG. 11 depicts XRD patterns of the zeolitesprepared having different Si/Al molar ratios. The results confirm thatzeolites with different Si/Al molar ratios all have highly crystallineMFI structures.

Example 14—Catalytic Testing of Prepared Mesoporous Zeolites

Two acid-catalyzed reactions were utilized to evaluate the catalyticperformance of mesoporous ZSM-5 zeolite having an Si/Al molar ratio of31 (as described in Example 6). The first test was the conversion ofmethanol to aromatics (MTA), which suffers from quick deactivation ofcatalyst due to the accumulation of coke. The second test was catalyticcracking of canola oil, which involves large-molecule reactants. Forcomparison, two conventional ZSM-5 zeolite catalysts which had differentparticle sizes were tested for the same reactions. These conventionalZSM-5 zeolites were the “micro ZSM-5 conventional zeolite” described inExample 6 (which has comparable particle size to the mesoporous ZSM-5zeolite, and the “nano ZSM-5 conventional zeolite” described in Example6 (which has a much larger particle size than the mesoporous ZSM-5zeolite).

Conversion of methanol to aromatics was performed in a stainlessfixed-bed reactor (internal diameter of 11 mm). 0.5 g of zeoliticcatalyst was used in each reaction. The catalyst bed was activated in apure air flow (50 mL/min) at 550° C. for 60 min prior to each run. Thenthe temperature was set to 550° C., and the air flow was switched to N₂(50 mL/min) gas flow with 0.02 mL/min feedstock (the weight ratio ofMeOH with 2-methylfuran is 4:1) using a HPLC pump. The weight hourlyspace velocity (WHSV) was about 2 g feedstock per gram catalyst perhour. All experiments were carried out under atmospheric pressure.Product analysis was performed using online gas chromatography. Theeffluent composition was determined on GC with a flame ionizationdetector (FID), equipped with Agilent HP-PLOT/Q column (30 m×0.53 mm×40μm). The following temperature programming was applied: 6° C./min from50° C. (5 min at the initial temperature) to 230° C. (20 min at thefinal temperature). Dimethyl ether was not considered as one productwhen doing the calculation.

The results of the temperature programmed desorption (TPD) of ammoniaexperiments show that mesoporous ZSM-5 zeolite is essentially identicalto micro ZSM-5 conventional zeolite in the type and strength of acidityexcept for slightly fewer strong acid sites. Nano ZSM-5 conventionalzeolite has a similar NH₃-TPD profile to micro ZSM-5 conventionalzeolite. Using a base-titration method, it was determined thatmesoporous ZSM-5 zeolite, nano ZSM-5 conventional zeolite, and microZSM-5 conventional zeolite have 29%, 12%, and 0% external Brønsted acidsites (accessible for molecules too large to enter the 10-ring channelsof ZSM-5), respectively. Specifically, to determine external acid cites,Organic base 2,6-di-tertbutylpyridine (DTBP) titration during ethanoldehydration reaction was used to determine the external acid sites ofzeolites, reactions were performed in a pulse reactor connected with anAgilent 7890A GC equipped with a FFAP capillary column. After treated inHe at 773 K for 2 hours, the catalysts (5.0 mg-11.0 mg, 100-300 mesh)were loaded in the reactor supported by glass wool. The temperature ofthe reactor was fixed at 415 K. 1 microliter (μL) of a mixture of2,6-di-tertbutylpyridine (DTBP, Alfa, 98% purity)/ethanol (0.0105 g/mL)was introduced by a liquid autosampler each pulse with 840 secondintervals until the titrant became saturated with the organic base. Thedehydration rate of ethanol was measured by the Agilent 7890A GCequipped with a FFAP capillary column. The loss in dehydration rate wascalculated by Equation #1. The loss in ethanol dehydration ratereflected the proportion of active sites accessible for bulky DTBPmolecules, which are defined as “external acid sites”. FIG. 23 depictsDTBP (2,6-di-tertbutylpyridine) base titration of acid sites on thethree zeolite catalysts during ethanol dehydration reactions.

                                    (Equation  #1)${{Rate}\mspace{14mu} {loss}\mspace{14mu} (\%)} = {\frac{{{initial}\mspace{14mu} {rate}\mspace{14mu} {of}\mspace{14mu} {dehyrdation}} - {{residual}\mspace{14mu} {rate}\mspace{14mu} {of}\mspace{14mu} {dehydration}}}{{initial}\mspace{14mu} {rate}\mspace{14mu} {of}\mspace{14mu} {dehydration}}*100\%}$

The MTA reaction was carried out using a fix-bed reactor at 550° C. withthe weight hourly space velocity (WHSV) of 2 g_(MeOH)/(g_(Cat)·hour).The conversion of methanol and selectivity of aromatics for the zeolitesis shown in FIG. 21A. Under this condition, the three catalysts couldfully convert methanol at the beginning of the reaction. High aromaticsselectivity (greater than 50%) was achieved by co-feeding MeOH with2-methylfuran (25 wt. %) to promote the aromatic-based catalytic cycle.A side effect of this co-feeding strategy was the quick formation ofcoke and the consequent deactivation of catalyst. Results showed thatthe deactivation rate has a direct correlation to the diffusion lengthof the catalyst. Specifically, micro ZSM-5 conventional zeolite lost 90%of its activity during only 2 hours of reaction; over nano ZSM-5conventional zeolite, the methanol conversion remained 100% up to 6hours and then dropped to about 40% at 10 hours; and the bestperformance was given by mesoporous ZSM-5 zeolite, which maintained 100%conversion of methanol for 11 hours, and its lifetime before theconversion dropped to about 40% was 14 hours. From the lifetime plots ofthe three catalysts, the conversion capacity R, the rate constant k, andthe deactivation coefficient a, were derived by using a model developedby Janssens in “Janssens, T. V. W., J. Catal. 264, 130-137 (2009)” incombination with the lifetime plots of each catalyst. Results are shownin Table 2. The results show that meso-ZSM-5 has a greater conversioncapacity, a higher rate constant, and a lower deactivation coefficient,compared to nano ZSM-5 and micro ZSM-5 conventional zeolite catalysts.The superior catalytic properties of mesoporous ZSM-5 zeolites may beattributed to its hierarchical structure, which allows the full use ofacid sites to achieve a high conversion rate and a large conversioncapacity, and meanwhile promotes molecular transport to reduce theprobability of coke formation and thus the catalyst deactivation. Inaddition, a hierarchical structure may increase the coke tolerancecapacity of the catalyst, which also accounts for the long lifetime ofmesoporous ZSM-5 zeolite. It is noted that during the reaction periodwith 100% methanol conversion, meso ZSM-5 zeolite showed a higherselectivity to aromatics than the two conventional ZSM-5 catalysts. Itshould be understood that for the data of Table 2, t_(0.5) refers totime until 50% of conversion, t_(0.8) refers to time until 80% ofconversion, R refers to the methanol conversion capacity calculated att_(0.5) (R=WHSV_(MeOH)*t_(0.5)), k refers to the rate constant derivedfrom Janssens' model at t_(0.8), and a refers to the deactivationcoefficient where a=τ₀/t_(0.5) (contact time τ₀=2.84 g_(cat) hmol_(MeOH) ⁻¹).

TABLE 2 R k α t_(0.5) t_(0.8) (mol_(MeOH) (mol_(MeOH) (g_(cat) Catalyst(h) (h) g_(Cat) ⁻¹) g_(Cat) ⁻¹ h⁻¹) mol_(meOH) ⁻¹) Meso ZSM-5 13.8 12.70.65 6.1 0.205 Nano ZSM-5 9.4 8.0 0.44 3.3 0.302 Micro ZSM-5 1.6 1.30.075 2.6 1.775

The catalytic cracking of canola oil (Abu Dhabi Vegetable Oil Company,100% pure) was carried out in a fixed-bed reactor at 550° C. Helium (25mL/min) was used as the carrier gas and nitrogen (12 mL/min) was used asinternal standard. Before reaction, the catalyst was crushed to 100-300μm size particles and activated in situ at 550° C. under helium flow (37mL/min) for 1 hour. A condenser was used to trap the water and liquidproducts. Gas phase products were analyzed using a Haixin 9200 GC systemequipped with FID and TCD detectors and HP-AL/KCL and TDX-01 columns.HP-AL/KCL column and FID were used for separation and analysis ofhydrocarbons, and TDX-01 column and TCD were used for separation andanalysis of nitrogen, CO_(x) and hydrogen. FID detector was maintainedat 573 K, and TCD detector was maintained at 523 K. The followingtemperature ramp was used: hold at 323 K for 10 min, ramp to 473 K at 10K/min and hold at 473 K for 20 minutes. Liquid products were analyzed byan Agilent 7890A GC equipped with a HP-5 capillary column.

FIG. 21(b) presents the conversion of canola oil and the yield of lightolefins versus contact time, from which it is shown that meso ZSM-5zeolites was able to convert more canola oil than nano ZSM-5conventional zeolite and micro ZSM-5 conventional zeolite at the samecondition. At contact time of 0.015 hour·g_(cat)/g_(oil), for example,the conversion of canola oil was 82.7 wt. % for mesoporous ZSM-5zeolite, 60.2 wt. % for nano ZSM-5 conventional zeolite, and 37.0 wt. %for micro ZSM-5 conventional zeolite. The corresponding yields of lightolefins were 26.9 wt. %, 16.4 wt. % and 10.1 wt. %, respectively.Detailed product distributions at different reaction conditions over thethree catalysts are provided in Tables 3-5, where Table 3 shows resultsfor mesoporous ZSM-5 zeolite, Table 4 shows results for nano ZSM-5conventional zeolite, and Table 5 shows results for micro ZSM-5conventional zeolite. The cracking of canola oil that mainly containsbulky saturated and unsaturated triglycerides is believed to begin withthe protonation of the fatty acid chain followed by β-scission. Due tothe large sizes of the reactant molecules, the protonation cannot takeplace in the micropores but only on the external surface of catalyst.Mesoporous ZSM-5 zeolite has the highest proportion of external acidsites among the three catalysts, and is therefore particularlyadvantageous for this reaction.

TABLE 3 W/F (h · g_(cat)/g_(oil)) 0.004 0.011 0.015 0.022 0.027Conversion (wt %) 33.1 64.6 82.7 97 100 Yield of products (wt %) CH₄ 0.30.5 0.7 1.7 0.8 C₂H₆ 0.4 0.8 1 2.2 1.2 C₂H₄ 1.9 4.5 6 8.7 7.6 C₃H₈ 0.51.2 1.2 1.2 2.4 C₃H₆ 4.3 9.8 14 14.4 15.1 i-C₄H₁₀ 0.2 0.4 0.5 0.4 1n-C₄H₁₀ 0.2 0.3 0.4 0.3 0.6 t-2-C₄H₈ 0.5 1.1 1.6 1.5 1.6 n-C₄H₈ 0.5 11.4 1.4 1.3 i-C₄H₈ 0.9 1.9 2.7 2.4 2.8 c-2-C₄H₈ 0.4 0.8 1.1 1.1 1.1 C₅0.9 1.7 2.4 2.2 2.2 C₆₊ and liquid products 15.1 27.5 33.2 40 41.9 Totalolefins 8.5 19.1 26.9 29.6 29.6 Total olefins and 23.6 46.7 60 69.6 71.5liquid products

TABLE 4 W/F (h · g_(cat)/g_(oil)) 0.004 0.011 0.015 0.022 0.027Conversion (wt %) 25.2 46.9 60.3 77.8 84.4 Yield of products (wt %) CH₄0.4 0.8 1.1 0.9 0.6 C₂H₆ 0.7 1.2 1.4 1.2 0.9 C₂H₄ 1.9 4.4 4.8 5.7 6.5C₃H₈ 0.3 0.7 0.5 1 1.1 C₃H₆ 1.9 6.9 7.8 12.9 14.1 i-C₄H₁₀ 0 0.2 0 0.30.3 n-C₄H₁₀ 0.1 0.2 0.2 0.3 0.3 t-2-C₄H₈ 0.2 0.7 1 1.5 1.5 n-C₄H₈ 0.40.8 1 1.4 1.4 i-C₄H₈ 0.2 1.1 1.3 2.5 2.5 c-2-C₄H₈ 0.1 0.5 0.7 1.1 1.1 C₅0.7 1.3 1.9 2.1 2.1 C₆₊ and liquid products 13.9 18.4 27.7 29.1 35.2Total olefins 4.7 14.4 16.4 25 27 Total olefins 18.7 32.9 44.1 54.1 62.2and liquid products

TABLE 5 W/F (h · g_(cat)/g_(oil)) 0.004 0.011 0.015 0.022 0.027Conversion (wt %) 14 33 37.1 45.8 53.6 Yield of products (wt %) CH₄ 0.20.9 1.4 1.5 1.2 C₂H₆ 0.4 1.2 2 2.1 1.6 C₂H₄ 0.9 3.2 5 5.7 5.3 C₃H₈ 0.20.3 0.5 0.5 0.9 C₃H₆ 0.5 1.9 3.2 4.4 4.8 i-C₄H₁₀ 0.1 0 0 0 0.1 n-C₄H₁₀ 00.1 0.2 0.1 0.2 t-2-C₄H₈ 0 0.1 0.2 0.4 0.4 n-C₄H₈ 0.2 0.5 1.1 1 0.7i-C₄H₈ 0 0.1 0.1 0.3 0.5 c-2-C₄H₈ 0 0.1 0.1 0.3 0.3 C₅ 0.3 0.8 1.4 1.71.2 C₆₊ and liquid products 8 12.4 14.1 18.8 20.5 Total olefins 1.6 69.7 12 11.9 Total olefins and 9.6 18.4 23.8 30.8 32.4 liquid products

Example 15—Synthesis of Functionalized Zeolites

The adsorption capability of uncalcined mesoporous ZSM-5 zeolite(without removing the template polymer) in comparison with aconventional ZSM-5 was demonstrated, where 50 mg of zeolite powder wasmixed with 1 mL of K₂PtCl₄ solution (0.013 M) for 5 minutes and thenseparated by centrifugation. The sharp contrast in color between the twosupernatants implied that mesoporous ZSM-5 zeolite adsorbed PtCl₄ ²⁻anions from the solution more efficiently than conventional ZSM-5. FIGS.25A and 25B show the adsorption of PtCl₄ ²⁻ by uncalcined mesoporousZSM-5 zeolite and by uncalcined nano ZSM-5 conventional zeolite.Specifically, FIGS. 25A and 25B show a photograph of 1 mL of 0.013-MK₂PtCl₄ aqueous solution alone (vial 0), mixed with 50 mg of mesoporousZSM-5 (vial 1), or mixed with 50 mg of nano ZSM-5 conventional zeolite(vial 2), before (FIG. 25A) and after (FIG. 25B) centrifugation. Thelighter color of the supernatant liquid in vial 1 compared to that invial 2 indicates a higher adsorption capacity of mesoporous ZSM-5.

The adsorption capacities (based on Pt) were determined by inductivelycoupled plasma-optical emission spectroscopy (ICP-OES) to be 24.7 mg/gfor meso-ZSM-5 and 0.64 mg/g for nano ZSM-5 conventional zeolite. Theenhanced adsorption capacity of mesoporous ZSM-5 zeoliteis attributed tothe abundant ammonium groups in PDAMAB-TPHAB that can capture PtCl₄ ²⁻anions through electrostatic interactions. After adsorption of PtCl₄ ²⁻,mesoporous ZSM-5 zeolite was calcined at 500° C. to remove the template,and meanwhile the Pt precursor was reduced to Pt metal. This processresulted in ultrafine Pt nanocrystals (1-2 nm) uniformly dispersed inmesoporous ZSM-5 zeolite were observed by high-angle annular dark-fieldscanning transmission electron microscopy (HAADF-STEM), confirming theadsorption of Pt ions by mesoporous ZSM-5 zeolite, as shown in FIG. 22.It is noted that by conventional wet impregnation methods, it isdifficult to prepare such small and well-dispersed Pt nanocrystals on azeolite support at such a loading level. It is believed that thespecific interaction between ammonium groups and PtCl₄ ²⁻ anions allowsthe latter uniformly distributed and protected by the polymer matrixresiding in mesoporous ZSM-5 zeolite particles, eventually leading tohighly dispersed ultrafine Pt nanocrystals upon calcination. Theresulting composite material integrates mesoporosity, strong acidity,and noble metal sites, and is potentially a useful catalyst forhydrogenation or hydrodeoxygenation involving large molecules.

For the purposes of describing and defining the present disclosure it isnoted that the term “about” is utilized in this disclosure to representthe inherent degree of uncertainty that may be attributed to anyquantitative comparison, value, measurement, or other representation.The term “about” are also utilized in this disclosure to represent thedegree by which a quantitative representation may vary from a statedreference without resulting in a change in the basic function of thesubject matter at issue. Additionally, the term “consisting essentiallyof” is used in this disclosure to refer to quantitative values that donot materially affect the basic and novel characteristic(s) of thedisclosure. For example, a chemical stream “consisting essentially” of aparticular chemical constituent or group of chemical constituents shouldbe understood to mean that the stream includes at least about 99.5% ofthat particular chemical constituent or group of chemical constituents.

It is noted that one or more of the following claims utilize the term“where” as a transitional phrase. For the purposes of defining thepresent technology, it is noted that this term is introduced in theclaims as an open-ended transitional phrase that is used to introduce arecitation of a series of characteristics of the structure and should beinterpreted in like manner as the more commonly used open-ended preambleterm “comprising.”

It should be understood that any two quantitative values assigned to aproperty may constitute a range of that property, and all combinationsof ranges formed from all stated quantitative values of a given propertyare contemplated in this disclosure.

According to a first aspect of the present disclosure, a cationicpolymer may comprise the structure of Chemical Structure #3 or ChemicalStructure #8, where A is nitrogen or phosphorus and B is nitrogen orphosphorus; where R5 is a branched or unbranched hydrocarbon chainhaving a carbon chain length of from 1 to 10,000 carbon atoms; whereeach of R6, R7, R8, R9, R10, R11, R12, and R13 are hydrogen atoms orhydrocarbons, and where each of the hydrocarbons optionally comprisesone or more heteroatoms; and where n is from 10 to 10,000,000.

A second aspect of the present disclosure may include the first aspect,where A and B are nitrogen.

A third aspect of the present disclosure may include the first or secondaspects, further comprising one or more anions selected from Cl⁻, Br⁻,F⁻, I⁻, OH⁻, ½SO₄ ²⁻, ⅓PO₄ ³⁻, ½S²⁻, AlO₂ ⁻.

A fourth aspect of the present disclosure may include any of the firstthrough third aspects, where R5 comprises a carbon chain length of from3 to 30 carbon atoms.

A fifth aspect of the present disclosure may include any of the firstthrough fourth aspects, where R5 comprises a carbon chain length of from5 to 10 carbon atoms.

A sixth aspect of the present disclosure may include any of the firstthrough fifth aspects, where R6, R7, R8, and R9 are hydrogen.

A seventh aspect of the present disclosure may include any of the firstthrough sixth aspects, where R10 is an alkyl group.

An eighth aspect of the present disclosure may include any of the firstthrough seventh aspects, where R10 is a methyl group.

A ninth aspect of the present disclosure may include any of the firstthrough eighth aspects, where R11, R12 and R13 are alkyl groups.

A tenth aspect of the present disclosure may include any of the firstthrough ninth aspects, where R11, R12 and R13 are methyl groups.

An eleventh aspect of the present disclosure may include any of thefirst through tenth aspects, where R11, R12 and R13 are ethyl groups.

A twelfth aspect of the present disclosure may include any of the firstthrough eleventh aspects, where R11, R12 and R13 are propyl groups.

A thirteenth aspect of the present disclosure may include any of thefirst through twelfth aspects, where the cationic polymer ispoly(N¹,N¹-diallyl-N¹-alkyl-N⁶,N⁶,N⁶-trialkylalkane-1,6-diamoniumhalide).

A fourteenth aspect of the present disclosure may include any of thefirst through thirteenth aspects, where the cationic polymer ispoly(N¹,N¹-diallyl-N¹-methyl-N⁶,N⁶,N⁶-trimethylhexane-1,6-diamoniumbromide).

A fifteenth aspect of the present disclosure may include any of thefirst through fourteenth aspects, where the cationic polymer ispoly(N¹,N¹-diallyl-N¹-methyl-N⁶,N⁶,N⁶-triethylhexane-1,6-diamoniumbromide).

A sixteenth aspect of the present disclosure may include any of thefirst through the fifteenth aspects, where the cationic polymer ispoly(N¹,N¹-diallyl-N¹-methyl-N⁶,N⁶,N⁶-tripropylhexane-1,6-diamoniumbromide).

A seventeenth aspect of the present disclosure may include any of thefirst through the sixteenth aspects, where the cationic polymer is anon-surfactant.

An eighteenth aspect of the present disclosure may include any of thefirst through the seventeenth aspects, where the cationic polymer isutilized as a structure-directing agent to form a mesoporous zeolite.

According to a nineteenth aspect of the present disclosure, a cationicpolymer comprising H-NMR peaks at one or more of: from 0.65 ppm to 1.05ppm; from 1.1 ppm to 1.5 ppm; from 1.4 ppm to 1.8 ppm; from 2.6 ppm to3.0 ppm; and from 2.85 ppm to 3.25 ppm.

A twentieth aspect of the present disclosure may include the nineteenthaspect, where the cationic polymer comprises H-NMR peaks at: from 0.65ppm to 1.05 ppm; from 1.1 ppm to 1.5 ppm; from 1.4 ppm to 1.8 ppm; from2.6 ppm to 3.0 ppm; and from 2.85 ppm to 3.25 ppm.

According to a twenty-first aspect of the present disclosure, a methodfor producing the cationic polymer comprises: forming a diallyl methylammonium hydrochloride cation with a chloride anion from diallylamine;polymerizing the diallyl methyl ammonium hydrochloride to form apoly(diallyl methyl ammonium hydrochloride) (PDMAH); forming apoly(diallyl methyl amine) (PDMA) from the poly(diallyl methyl ammoniumhydrochloride) (PDMAH); forming an ammonium halide cation with a halideanion by reacting a trialkyl amine with a dihaloalkane; and forming thecationic polymer of claim 1 by reacting the PDMA with the ammoniumhalide cation.

A twenty-second aspect of the present disclosure may include thetwenty-first aspect, where the cationic polymer comprises the structureof Chemical Structure #3 or Chemical Structure #8, where A is nitrogenor phosphorus and B is nitrogen or phosphorus; where R5 is a branched orunbranched hydrocarbon chain having a carbon chain length of from 1 to10,000 carbon atoms; where each of R6, R7, R8, R9, R10, R11, R12, andR13 are hydrogen atoms or hydrocarbons, and where each of thehydrocarbons optionally comprises one or more heteroatoms; and where nis from 10 to 10,000,000.

A twenty-third aspect of the present disclosure may include thetwenty-first or twenty-second aspects, where the diallyl methyl ammoniumhydrochloride cation with a chloride anion is formed by contacting thediallylamine with formic acid, formaldehyde, and HCl.

A twenty-fourth aspect of the present disclosure may include any of thetwenty-first to twenty-third aspects, where the diallyl methyl ammoniumhydrochloride is polymerized by contact with2,2′-axobis(2-methylpropionamidine) dihydrochloride (AAPH).

A twenty-fifth aspect of the present disclosure may include any of thetwenty-first to twenty-fourth aspects, where the poly(diallyl methylamine) (PDMA) is formed by contacting the poly(diallyl methyl ammoniumhydrochloride) (PDMAH) with methane and sodium methoxide.

According to a twenty-sixth aspect of the present disclosure, a catalystmay be produced by utilizing a cationic polymer as a structure-directingagent, where the cationic polymer utilized as the structure-directingagent comprises the structure of Chemical Structure #3 or ChemicalStructure #8, where A is nitrogen or phosphorus and B is nitrogen orphosphorus; where R5 is a branched or unbranched hydrocarbon chainhaving a carbon chain length of from 1 to 10,000 carbon atoms; whereeach of R6, R7, R8, R9, R10, R11, R12, and R13 are hydrogen atoms orhydrocarbons, and where each of the hydrocarbons optionally comprisesone or more heteroatoms; and where n is from 10 to 10,000,000.

A twenty-seventh aspect of the present disclosure may include thetwenty-sixth aspect, where the catalyst is a mesoporous zeolite.

According to a twenty-eighth aspect of the present disclosure, amesoporous zeolite may be produced by a method comprising: combining acationic polymer and one or more precursor materials to form anintermediate material comprising micropores, where: the cationic polymeracts as a structure-directing agent for the formation of the micropores;and the cationic polymer comprises monomers that comprise two or morequaternary ammonium cations or quaternary phosphonium cations connectedby a hydrocarbon chain; and calcining the intermediate structure formthe mesoporous zeolite.

A twenty-ninth aspect of the present disclosure may include thetwenty-eighth aspect, where the calcining removes the cationic polymerfrom the intermediate structure and forms mesopores.

A thirtieth aspect of the present disclosure may include any of thetwenty-eighth or twenty-ninth aspects, where the cationic polymercomprises the structure of Chemical Structure #3 or Chemical Structure#8, where A is nitrogen or phosphorus and B is nitrogen or phosphorus;where R5 is a branched or unbranched hydrocarbon chain having a carbonchain length of from 1 to 10,000 carbon atoms; where each of R6, R7, R8,R9, R10, R11, R12, and R13 are hydrogen atoms or hydrocarbons, and whereeach of the hydrocarbons optionally comprises one or more heteroatoms;and where n is from 10 to 10,000,000.

A thirty-first aspect of the present disclosure may include any of thetwenty-eighth to thirtieth aspects, where the precursor materials areselected from one or more of a silicon-containing material, atitanium-containing material, and an aluminum-containing material.

A thirty-second aspect of the present disclosure may include any of thetwenty-eighth to thirty-first aspects, where the mesoporous zeolitecomprises an aluminosilicate material, a titanosilicate material, or apure silicate material.

A thirty-third aspect of the present disclosure may include any of thetwenty-eighth to thirty-second aspects, where the mesoporous zeolitecomprises a surface area of greater than 350 m²/g.

A thirty-fourth aspect of the present disclosure may include any of thetwenty-eighth to thirty-third aspects, where the mesoporous zeolitecomprises a pore volume of greater than 0.3 cm³/g.

A thirty-fifth aspect of the present disclosure may include any of thetwenty-eighth to thirty-fourth aspects, where the mesoporous zeolitecomprises a MFI framework type.

A thirty-sixth aspect of the present disclosure may include any of thetwenty-eighth to thirty-fifth aspects, where the mesoporous zeolite is aZSM-5 zeolite.

A thirty-seventh aspect of the present disclosure may include any of thetwenty-eighth to thirty-sixth aspects, where the mesoporous zeolite is aTS-1 zeolite.

A thirty-eighth aspect of the present disclosure may include any of thetwenty-eighth to thirty-seventh aspects, where the mesoporous zeolite isa silicalite-I zeolite.

A thirty-ninth aspect of the present disclosure may include any of thetwenty-eighth to thirty-eighth aspects, where the mesoporous zeolitecomprises a BEA framework type.

A fortieth aspect of the present disclosure may include any of thetwenty-eighth to thirty-ninth aspects, where the mesoporous zeolite is aBeta zeolite.

According to a forty-first aspect of the present disclosure, amesoporous zeolite may comprise: a microporous framework comprising aplurality of micropores having diameters of less than or equal to 2 nm;and a plurality of mesopores having diameters of greater than 2 nm andless than or equal to 50 nm; where the mesoporous zeolite comprises analuminosilicate material, a titanosilicate material, or a pure silicatematerial; where the mesoporous zeolite comprises a surface area ofgreater than 350 m²/g; and where the mesoporous zeolite comprises a porevolume of greater than 0.3 cm³/g.

A forty-second aspect of the present disclosure may include theforty-first aspect, where the mesoporous zeolite comprises a MFIframework type.

A forty-third aspect of the present disclosure may include any of theforty-first to forty-second aspects, where the mesoporous zeolite is aZSM-5 zeolite.

A forty-forth aspect of the present disclosure may include any of theforty-first through forty-third aspects, where the mesoporous zeolite isa TS-1 zeolite.

A forty-fifth aspect of the present disclosure may include any of theforty-first through forty-forth aspects, where the mesoporous zeolite isa silicalite-I zeolite.

A forty-sixth aspect of the present disclosure may include any of theforty-first through forty-fifth aspects, where the mesoporous zeolitecomprises a BEA framework type.

A forty-seventh aspect of the present disclosure may include any of theforty-first through forty-sixth aspects, where the mesoporous zeolite isa Beta zeolite.

A forty-eighth aspect of the present disclosure may include any of theforty-first through forty-seventh aspects, where the mesoporous zeolitecomprises an aluminosilicate material.

A forty-ninth aspect of the present disclosure may include any of theforty-first through forty-eighth aspects, where the mesoporous zeolitecomprises a molar ratio of Si to Al of greater than or equal to 10.

A fiftieth aspect of the present disclosure may include any of theforty-first through forty-ninth aspects, where the mesoporous zeolitecomprises a titanosilicate material.

A fifty-first aspect of the present disclosure may include any of theforty-first through fiftieth aspects, where the mesoporous zeolitecomprises a molar ratio of Si to Ti of greater than or equal to 30.

A fifty-second aspect of the present disclosure may include any of theforty-first through fifty-first aspects, where the mesoporous zeolitecomprises a pure silicate material.

A fifty-third aspect of the present disclosure may include any of theforty-first through fifty-second aspects, where the mesoporous zeolitecomprises particles of from 25 nm to 500 nm in size.

According to a fifty-fourth aspect of the present disclosure, a porousmaterial may comprise: a zeolite core portion comprising a microporousstructure comprising a plurality of micropores having a diameter of lessthan or equal to 2 nm, where the core portion comprises analuminosilicate material, a titanosilicate material, or a pure silicatematerial; a mesoporous zeolite shell portion that comprises analuminosilicate material, a titanosilicate material, or a pure silicatematerial and surrounds the core portion, the shell portion comprising: amicroporous framework comprising a plurality of micropores havingdiameters of less than or equal to 2 nm; and a plurality of mesoporeshaving diameters of greater than 2 nm and less than or equal to 50 nm.

A fifty-fifth aspect of the present disclosure may include thefifty-fourth aspect, where the shell portion comprises a surface area ofgreater than 350 m²/g.

A fifty-sixth aspect of the present disclosure may include thefifty-fourth or fifty-fifth aspects, where the shell portion comprises apore volume of greater than 0.3 cm³/g.

A fifty-seventh aspect of the present disclosure may include any of thefifty-fourth through fifty-sixth aspects, where the core portion doesnot comprise mesopores.

A fifty-eighth aspect of the present disclosure may include any of thefifty-fourth through fifty-seventh aspects, where the shell portion hasa thickness of from 20 nm to 200 nm.

A fifty-ninth aspect of the present disclosure may include any of thefifty-fourth through fifty-eighth aspects, where the core portion has alength of from 25 nm to 500 nm.

A sixtieth aspect of the present disclosure may include any of thefifty-fourth through fifty-ninth aspects, where the shell portioncomprises a MFI framework type.

A sixty-first aspect of the present disclosure may include any of thefifty-fourth through sixtieth aspects, where the shell portion is aZSM-5 zeolite.

A sixty-second aspect of the present disclosure may include any of thefifty-fourth through sixty-first aspects, where the shell portion is aTS-1 zeolite.

A sixty-third aspect of the present disclosure may include any of thefifty-fourth through sixty-second aspects, where the shell portion is asilicalite-I zeolite.

A sixty-fourth aspect of the present disclosure may include any of thefifty-fourth through sixty-fourth aspects, where the shell portioncomprises a BEA framework type.

A sixty-fifth aspect of the present disclosure may include any of thefifty-fourth through sixty-fourth aspects, where the shell portion is aBeta zeolite.

According to a sixty-sixth aspect of the present disclosure, acore/shell zeolite comprising a core portion and a shell portion may beproduced by a method comprising: forming a mixture comprising a cationicpolymer, precursor materials of the porous material, and one or morecore seed materials, the core seed materials comprising a microporousstructure; forming the shell portion intermediate material around thecore seed material, the shell portion intermediate material comprisingmicropores, where: the cationic polymer acts as a structure-directingagent for the formation of the micropores of the shell portionintermediate; and the cationic polymer comprises monomers that comprisetwo or more quaternary ammonium cations or quaternary phosphoniumcations separated by a hydrocarbon chain; and calcining the core/shellporous material to form a core/shell zeolite, where the shell portioncomprises a mesoporous zeolite.

A sixty-seventh aspect of the present disclosure may include thesixty-sixth aspect, where the cationic polymer comprises the structureof Chemical Structure #3 or Chemical Structure #8, where A is nitrogenor phosphorus and B is nitrogen or phosphorus; where R5 is a branched orunbranched hydrocarbon chain having a carbon chain length of from 1 to10,000 carbon atoms; where each of R6, R7, R8, R9, R10, R11, R12, andR13 are hydrogen atoms or hydrocarbons, and where each of thehydrocarbons optionally comprises one or more heteroatoms; and where nis from 10 to 10,000,000.

A sixty-eighth aspect of the present disclosure may include thesixty-sixth or sixty seventh aspect, where the calcining removes thecationic polymer from the shell portion intermediate structure and formsmesopores in the shell structure.

A sixty-ninth aspect of the present disclosure includes a cationicpolymer comprising the structure:

where A is nitrogen or phosphorus and B is nitrogen or phosphorus; whereR5 is a branched or unbranched hydrocarbon chain having a carbon chainlength of from 1 to 10,000 carbon atoms; where each of R6, R7, R8, R9,R10, R11, R12, and R13 are hydrogen atoms or hydrocarbons, and whereeach of the hydrocarbons optionally comprises one or more heteroatoms;and where o+m is from 10 to 10,000,000.

Having described the subject matter of the present disclosure in detailand by reference to specific embodiments, it is noted that the variousdetails described in this disclosure should not be taken to imply thatthese details relate to elements that are essential components of thevarious embodiments described in this disclosure, even in cases where aparticular element is illustrated in each of the drawings that accompanythe present description. Rather, the claims appended hereto should betaken as the sole representation of the breadth of the presentdisclosure and the corresponding scope of the various embodimentsdescribed in this disclosure. Further, it will be apparent thatmodifications and variations are possible without departing from thescope of the appended claims.

What is claimed is:
 1. A cationic polymer comprising the structure:

where A is nitrogen or phosphorus and B is nitrogen or phosphorus; whereR5 is a branched or unbranched hydrocarbon chain having a carbon chainlength of from 1 to 10,000 carbon atoms; where each of R6, R7, R8, R9,R10, R11, R12, and R13 are hydrogen atoms or hydrocarbons, and whereeach of the hydrocarbons optionally comprises one or more heteroatoms;and where n is from 10 to 10,000,000.
 2. The cationic polymer of claim1, further comprising one or more anions selected from Cl⁻, Br⁻, F⁻, I⁻,OH⁻, ½SO₄ ²⁻, ⅓PO₄ ³⁻, ½S²⁻, AlO₂ ⁻.
 3. The cationic polymer of claim 1,where R5 comprises a carbon chain length of from 3 to 30 carbon atoms.4. The cationic polymer of claim 1, where R5 comprises a carbon chainlength of from 5 to 10 carbon atoms.
 5. A method for producing thecationic polymer, the method comprising: forming a diallyl methylammonium hydrochloride cation with a chloride anion from diallylamine;polymerizing the diallyl methyl ammonium hydrochloride to form apoly(diallyl methyl ammonium hydrochloride) (PDMAH); forming apoly(diallyl methyl amine) (PDMA) from the poly(diallyl methyl ammoniumhydrochloride) (PDMAH); forming an ammonium halide cation with a halideanion by reacting a trialkyl amine with a dihaloalkane; and forming thecationic polymer of claim 1 by reacting the PDMA with the ammoniumhalide cation.
 6. The method of claim 5, where the cationic polymercomprises the structure:

where A is nitrogen or phosphorus and B is nitrogen or phosphorus; whereR5 is a branched or unbranched hydrocarbon chain having a carbon chainlength of from 1 to 10,000 carbon atoms; where each of R6, R7, R8, R9,R10, R11, R12, and R13 are hydrogen atoms or hydrocarbons, and whereeach of the hydrocarbons optionally comprises one or more heteroatoms;and where n is from 10 to 10,000,000.
 7. The method of claim 5, wherethe diallyl methyl ammonium hydrochloride cation with a chloride anionis formed by contacting the diallylamine with formic acid, formaldehyde,and HCl.
 8. The method of claim 5, where the diallyl methyl ammoniumhydrochloride is polymerized by contact with2,2′-axobis(2-methylpropionamidine) dihydrochloride (AAPH).
 9. Themethod of claim 5, where the poly(diallyl methyl amine) (PDMA) is formedby contacting the poly(diallyl methyl ammonium hydrochloride) (PDMAH)with methane and sodium methoxide.
 10. A catalyst produced by utilizinga cationic polymer as a structure-directing agent, where the cationicpolymer utilized as the structure-directing agent comprises thestructure:

where A is nitrogen or phosphorus and B is nitrogen or phosphorus; whereR5 is a branched or unbranched hydrocarbon chain having a carbon chainlength of from 1 to 10,000 carbon atoms; where each of R6, R7, R8, R9,R10, R11, R12, and R13 are hydrogen atoms or hydrocarbons, and whereeach of the hydrocarbons optionally comprises one or more heteroatoms;and where n is from 10 to 10,000,000.
 11. The catalyst of claim 10,where the catalyst is a mesoporous zeolite.
 12. A method for producing amesoporous zeolite, the method comprising: combining a cationic polymerand one or more precursor materials to form an intermediate materialcomprising micropores, where: the cationic polymer acts as astructure-directing agent for the formation of the micropores; and thecationic polymer comprises monomers that comprise two or more quaternaryammonium cations or quaternary phosphonium cations connected by ahydrocarbon chain; and calcining the intermediate structure form themesoporous zeolite.
 13. The method of claim 12, where the calciningremoves the cationic polymer from the intermediate structure and formsmesopores.
 14. The method of claim 12, where the cationic polymercomprises the structure:

where A is nitrogen or phosphorus and B is nitrogen or phosphorus; whereR5 is a branched or unbranched hydrocarbon chain having a carbon chainlength of from 1 to 10,000 carbon atoms; where each of R6, R7, R8, R9,R10, R11, R12, and R13 are hydrogen atoms or hydrocarbons, and whereeach of the hydrocarbons optionally comprises one or more heteroatoms;and where n is from 10 to 10,000,000.
 15. The method of claim 12, wherethe precursor materials are selected from one or more of asilicon-containing material, a titanium-containing material, and analuminum-containing material.
 16. The method of claim 12, where themesoporous zeolite comprises an aluminosilicate material, atitanosilicate material, or a pure silicate material.
 17. A cationicpolymer comprising the structure:

where A is nitrogen or phosphorus and B is nitrogen or phosphorus; whereR5 is a branched or unbranched hydrocarbon chain having a carbon chainlength of from 1 to 10,000 carbon atoms; where each of R6, R7, R8, R9,R10, R11, R12, and R13 are hydrogen atoms or hydrocarbons, and whereeach of the hydrocarbons optionally comprises one or more heteroatoms;and where o+m is from 10 to 10,000,000.
 18. The cationic polymer ofclaim 17, where A and B are nitrogen.
 19. The cationic polymer of claim17, further comprising one or more anions selected from Cl⁻, Br⁻, F⁻,I⁻, OH⁻, ½SO₄ ², ⅓PO₄ ³⁻, ½S²⁻, AlO₂ ⁻.
 20. The cationic polymer ofclaim 17, where R5 comprises a carbon chain length of from 3 to 30carbon atoms.